U.S. patent application number 13/833230 was filed with the patent office on 2014-03-13 for production of polyhydroxyalkanoates with a defined composition from an unrelated carbon source.
This patent application is currently assigned to WISCONSIN ALUMNI RESEARCH FOUNDATION. The applicant listed for this patent is WISCONSIN ALUMNI RESEARCH FOUNDATION. Invention is credited to DANIEL E. AGNEW, BRIAN FREDERICK PFLEGER.
Application Number | 20140073022 13/833230 |
Document ID | / |
Family ID | 50233645 |
Filed Date | 2014-03-13 |
United States Patent
Application |
20140073022 |
Kind Code |
A1 |
PFLEGER; BRIAN FREDERICK ;
et al. |
March 13, 2014 |
PRODUCTION OF POLYHYDROXYALKANOATES WITH A DEFINED COMPOSITION FROM
AN UNRELATED CARBON SOURCE
Abstract
Cells and methods for producing polyhydroxyalkanoates. The cells
comprise one or more recombinant genes selected from an R-specific
enoyl-CoA hydratase gene, a PHA polymerase gene, a thioesterase
gene, and an acyl-CoA-synthetase gene. The cells further have one
or more genes functionally deleted. The functionally deleted genes
include such genes as an enoyl-CoA hydratase gene, a
3-hydroxyacyl-CoA dehydrogenase, and a 3-ketoacyl-CoA thiolase
gene. The recombinant cells are capable of using producing
polyhydroxyalkanoates with a high proportion of monomers having the
same carbon length from non-lipid substrates, such as
carbohydrates.
Inventors: |
PFLEGER; BRIAN FREDERICK;
(MADISON, WI) ; AGNEW; DANIEL E.; (MADISON,
WI) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
WISCONSIN ALUMNI RESEARCH FOUNDATION |
MADISON |
WI |
US |
|
|
Assignee: |
WISCONSIN ALUMNI RESEARCH
FOUNDATION
MADISON
WI
|
Family ID: |
50233645 |
Appl. No.: |
13/833230 |
Filed: |
March 15, 2013 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61699044 |
Sep 10, 2012 |
|
|
|
Current U.S.
Class: |
435/135 ;
435/252.3 |
Current CPC
Class: |
C12N 9/1029 20130101;
C12N 9/0006 20130101; C12Y 402/01017 20130101; C12P 7/625 20130101;
C12P 7/62 20130101; C12N 9/88 20130101; C12Y 101/01035 20130101;
C12N 9/93 20130101; C12N 9/16 20130101 |
Class at
Publication: |
435/135 ;
435/252.3 |
International
Class: |
C12P 7/62 20060101
C12P007/62 |
Goverment Interests
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH
[0002] This invention was made with government support under
DE-FC02-07ER64494 awarded by the US Department of Energy. The
government has certain rights in the invention.
Claims
1. A recombinant cell for producing polyhydroxyalkanoate comprising
one or more recombinant genes selected from the group consisting of
an R-specific enoyl-CoA hydratase gene, a PHA polymerase gene, a
thioesterase gene, and an acyl-CoA-synthetase gene, wherein a gene
product from a gene selected from the group consisting of an
enoyl-CoA hydratase gene, a 3-hydroxyacyl-CoA dehydrogenase, and a
3-ketoacyl-CoA thiolase gene is functionally deleted, and wherein
the recombinant cell is capable of producing
polyhydroxyalkanoate.
2. The recombinant cell of claim 1 wherein the recombinant cell is
a microbial cell.
3. The recombinant cell of claim 1 wherein the recombinant cell is
a bacterial cell.
4. The recombinant cell of claim 1 wherein the enoyl-CoA hydratase
gene is selected from the group consisting of fadB and fadJ.
5. The recombinant cell of claim 1 wherein the 3-hydroxyacyl-CoA
dehydrogenase gene is selected from the group consisting of fadB
and fadJ.
6. The recombinant cell of claim 1 wherein the 3-ketoacyl-CoA
thiolase gene is selected from the group consisting of fadA and
fadI.
7. The recombinant cell of claim 1 wherein gene products of fadA
and fadI; fadB and fadJ; or fadA, fadI, fadB and fadJ are
functionally deleted.
8. The recombinant cell of claim 1 wherein a gene product of fadR
is functionally deleted.
9. The recombinant cell of claim 1 wherein gene products of fadA
and fadI; fad R, fadA, and fadI; fadB and fadJ; fad R, fadB, and
fadJ; fadA, fadB, fadI, and fadJ; or fad R, fadA, fadB, fadI, and
fadJ are functionally deleted.
10. The recombinant cell of claim 1 wherein the enoyl-CoA hydratase
gene is a phaJ gene.
11. The recombinant cell of claim 1 wherein the PHA polymerase gene
is a phaC gene.
12. The recombinant cell of claim 1 wherein the enoyl-CoA hydratase
gene is phaJ3 and the PHA polymerase gene is phaC2.
13. The recombinant cell of claim 1 wherein the thioesterase gene
is Umbellularia californica thioesterase or a homolog thereof.
14. The recombinant cell of claim 1 wherein the acyl-CoA-synthetase
gene is PP.sub.--0763 from P. putida.
15. The recombinant cell of claim 1 further comprising a
recombinant phasin gene.
16. The recombinant cell of claim 1 comprising the R-specific
enoyl-CoA hydratase gene, the PHA polymerase gene, the thioesterase
gene, and the acyl-CoA-synthetase gene, wherein the recombinant
cell is capable of producing polyhydroxyalkanoate from carbohydrate
in a medium devoid of a fatty acid source.
17. The recombinant cell of claim 16 wherein gene products of fadA
and fadI; fad R, fadA, and fadI; fadB and fadJ; fad R, fadB, and
fadJ; fadA, fadB, fadI, and fadJ; or fad R, fadA, fadB, fadI, and
fadJ are functionally deleted.
18. A method of producing polyhydroxyalkanoate comprising culturing
a recombinant cell as recited in claim 1.
19. The method of claim 18 comprising culturing the recombinant
cell in aerobic conditions.
20. The method of claim 18 comprising culturing the recombinant
cell in a medium comprising a carbohydrate and substantially devoid
of a fatty acid source.
21. The method of claim 18 wherein the culturing produces
polyhydroxyalkanoate to at least about 7.5% cell dry weight.
22. The method of claim 18 wherein the culturing produces
polyhydroxyalkanoate comprised of hydroxyalkanoate monomers,
wherein greater than about 50% of the hydroxyalkanoate monomers
comprise hydrocarbon chains comprising same number of carbons.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority under 35 USC .sctn.119(e)
to U.S. Provisional Patent Application 61/699,044 filed Sep. 10,
2012, the entirety of which is incorporated herein by
reference.
FIELD OF THE INVENTION
[0003] The present invention is directed to cells and methods for
producing polyhydroxyalkanoates having a defined monomeric
composition at a high yield from an unrelated carbon source.
BACKGROUND
[0004] Polyhydroxyalkanoates (PHA) are a class of microbially
synthesized polyesters that are produced in large quantities as a
form of carbon and energy storage. Natural PHA possesses structural
properties that make it attractive as a renewable plastic for
select applications. However, most naturally produced PHA contains
random monomeric sequences, as the organism adds whatever monomers
are present in large enough quantities to the PHA polymer. Such PHA
polymers with random monomeric sequences are often not desirable
for specific commercial applications. By changing the identity
and/or percentage of co-monomers, the structural properties of PHA
can be engineered with varying degrees of crystallinity and
elasticity (Khanna and Srivastava, 2005).
[0005] A wide range of hydroxy-acids have been incorporated as
monomers into PHA chains when fed to PHA accumulating organisms
(Meng et al., 2012; Steinbuchel and Valentin, 1995; Zhou et al.,
2011). However, this strategy requires an external source of each
monomer or monomer precursor (e.g., fatty acids), and low-cost
sources of such monomers or monomer precursors are not currently
available. For this reason, current PHA research is focused on
engineering metabolic pathways to produce monomers from unrelated
carbon sources such as glucose (Li et al., 2010; Theodorou et al.,
2012).
[0006] Medium-chain-length PHA (mcl-PHA), which consists of fatty
acids containing six or more carbons, is an attractive polymer,
desired for novel applications in medical devices, cosmetics, and
tissue engineering (Chen and Wu, 2005). Bacteria that naturally
produce mcl-PHA incorporate monomers derived from either fatty acid
biosynthesis or degradation (.beta.-oxidation) pathways. Efforts to
enhance production of mcl-PHA have used metabolic engineering to
enhance these pathways. See, e.g., U.S. Pat. No. 5,480,794 to
Peoples et al., U.S. Pat. No. 6,593,116 to Huisman et al., U.S.
Pat. No. 6,759,219 to Hein et al., U.S. Pat. No. 6,913,911 to
Huisman et al., U.S. Pat. No. 7,786,355 Aguin et al., U.S. Pat. No.
7,968,325 to Hein et al., and other references cited herein.
However, production of mcl-PHA at high yields from an unrelated
carbon source has not been achieved.
[0007] Methods and tools for making PHA having a specific monomeric
composition, such as mcl-PHA, at a high yield using abundant,
inexpensive, and renewable precursors, such as glucose, are
needed.
SUMMARY OF THE INVENTION
[0008] A specific version of the present invention uses an
engineered metabolic pathway for converting glucose into
medium-chain-length (mcl)-PHA composed primarily of
3-hydroxydodecanoate monomers. This pathway combines fatty acid
biosynthesis, an acyl-ACP thioesterase to generate desired C.sub.12
and C.sub.14 fatty acids, .beta.-oxidation for conversion of fatty
acids to (R)-3-hydroxyacyl-CoAs, and a PHA polymerase. Expressing
an acyl-CoA synthetase, deleting enzymes involved in
.beta.-oxidation under aerobic conditions (e.g., fadR, fadA, fadB,
fadI, and/or fadJ), and overexpressing an acyl-ACP thioesterase
(BTE), an enoyl-CoA hydratase (phaJ3), and mcl-PHA polymerase
(phaC2) in a microorganism such as E. coli enables production
polyhydroxydodecanoate from glucose under aerobic conditions at
yields over 15% cell dry weight (CDW). This is the highest reported
production of mcl-PHA of a defined composition from an unrelated
carbon source.
[0009] The invention provides recombinant cells and methods for
producing polyhydroxyalkanoates.
[0010] A version of a recombinant cell of the present invention
comprises one or more recombinant genes selected from the group
consisting of an R-specific enoyl-CoA hydratase gene, a PHA
polymerase gene, a thioesterase gene, and an acyl-CoA-synthetase
gene, wherein a gene product from a gene selected from the group
consisting of an enoyl-CoA hydratase gene, a 3-hydroxyacyl-CoA
dehydrogenase, and a 3-ketoacyl-CoA thiolase gene is functionally
deleted, and wherein the recombinant cell is capable of producing
polyhydroxyalkanoate.
[0011] The recombinant cell may be a microbial cell, such as a
bacterial cell.
[0012] In some versions, the enoyl-CoA hydratase gene is selected
from the group consisting of fadB and fadJ.
[0013] In some versions, the 3-hydroxyacyl-CoA dehydrogenase gene
is selected from the group consisting of fadB and fadJ.
[0014] In some versions, the 3-ketoacyl-CoA thiolase gene is
selected from the group consisting of fadA and fadI.
[0015] In some versions, the gene products of fadA and fadI; fadB
and fadJ; or fadA, fadI, fadB and fadJ are functionally
deleted.
[0016] In some versions, the gene product of fadR is functionally
deleted.
[0017] In some versions, gene products of fadA and fadI; fad R,
fadA, and fadI; fadB and fadJ; fad R, fadB, and fadJ; fadA, fadB,
fadI, and fadJ; or fad R, fadA, fadB, fadI, and fadJ are
functionally deleted.
[0018] In some versions, the enoyl-CoA hydratase gene is a phaJ
gene.
[0019] In some versions, the PHA polymerase gene is a phaC
gene.
[0020] In some versions, the enoyl-CoA hydratase gene is phaJ3 and
the PHA polymerase gene is phaC2.
[0021] In some versions, the thioesterase gene is Umbellularia
californica thioesterase or a homolog thereof.
[0022] In some versions, the acyl-CoA-synthetase gene is
PP.sub.--0763 from P. putida.
[0023] In some versions, the cell further comprises a recombinant
phasin gene.
[0024] In some versions, the recombinant cell comprises each of a
recombinant R-specific enoyl-CoA hydratase gene, a recombinant PHA
polymerase gene, a recombinant thioesterase gene, and a recombinant
acyl-CoA-synthetase gene, wherein the recombinant cell is capable
of producing polyhydroxyalkanoate from carbohydrate in a medium
devoid of a fatty acid source.
[0025] A version of a method of the present invention comprises
culturing a recombinant cell as described herein.
[0026] Some versions comprise culturing the recombinant cell in
aerobic conditions.
[0027] Some versions comprise culturing the recombinant cell in a
medium comprising a carbohydrate and substantially devoid of a
fatty acid source.
[0028] In some versions, the culturing produces
polyhydroxyalkanoate to at least about 7.5% cell dry weight.
[0029] In some versions, the culturing produces
polyhydroxyalkanoate comprised of hydroxyalkanoate monomers,
wherein greater than about 50% of the hydroxyalkanoate monomers
comprise hydrocarbon chains comprising same number of carbons.
[0030] The objects and advantages of the invention will appear more
fully from the following detailed description of the preferred
embodiment of the invention made in conjunction with the
accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0031] FIG. 1 depicts a schematic of a metabolic pathway for
mcl-PHA biosynthesis in E. coli. A carbon source (i.e., glucose) is
catabolized to acetyl-CoA which enters fatty acid biosynthesis for
production of fatty acyl-ACPs. C.sub.12 and C.sub.14 acyl-ACPs are
substrates for the thioesterase, BTE, which catalyzes FFA
formation. An acyl-CoA synthetase (e.g., FadD) activates the FFAs
for degradation via a partially intact .beta.-oxidation cycle
generating enoyl-CoAs which PhaJ hydrates to produce mcl-PHA
monomers for polymerization by PhaC. The resulting monomer
composition is therefore identical to that of the FFA pool
generated by the thioesterase. FadR represses expression of
.beta.-oxidation genes in the absence of acyl-CoAs.
[0032] FIG. 2 A shows the metabolism of exogenously fed dodecanoic
acid after 24 and 48 h of shake flask cultivation as a percent of
the initial fatty acid concentration by a library of E. coli
.beta.-oxidation knock-out strains harboring the specific fad
deletion(s) indicated on the horizontal axis (e.g., K12=E. coli
K-12 MG1655; R=E. coli K-12 MG1655 .DELTA.fadR; etc.). Data for
both saturated (C.sub.12:0) and total C.sub.12 (including
unsaturated and hydroxy) species are presented.
[0033] FIG. 2B shows the metabolism of endogenously synthesized
fatty acids in strains with plasmid-based expression of BTE after
48 h of cultivation by a library of E. coli .beta.-oxidation
knock-out strains harboring the specific fad deletion(s) indicated
on the horizontal axis (e.g., K12=E. coli K-12 MG1655; R=E. coli
K-12 MG1655 .DELTA.fadR; etc.). Data for both saturated
(C.sub.12:0) and total C.sub.12 (including unsaturated and hydroxy)
species are presented.
[0034] FIG. 3 shows a comparison of the effect of a fadR deletion
with fadD overexpression via a chromosomal fusion of the trc
promoter (.PHI.(P.sub.trc-fadD)) on exogenous dodecanoic acid
metabolism in E. coli over a 24 h period. Data is presented as a
percent of the initial fatty acid concentration.
[0035] FIG. 4A shows the titer of PHA as a percentage of dry cell
weight (CDW) for mcl-PHA produced in E. coli in the presence of
exogenously fed dodecanoic acid or endogenously produced FFA.
Strain .DELTA.fadRABIJ was cultured in the presence of dodecanoic
acid while SA01 (expressing BTE) was capable of endogenous FFA
production in glucose minimal media. CDW was determined by
quantifying 3-hydroxy fatty acid methyl esters from a PHA
extraction. See Table 5 for individual CDW and PHA titer values
[0036] FIG. 4B shows the titer of fatty acids in E. coli producing
mcl-PHA in the presence of exogenously fed dodecanoic acid or
endogenously produced FFA. Strain .DELTA.fadRABIJ was cultured in
the presence of dodecanoic acid while SA01 (expressing BTE) was
capable of endogenous FFA production in glucose minimal media. The
titer of fatty acids was determined by quantifying fatty acid
methyl esters (FAME) from a total lipid extraction.
[0037] FIG. 5A shows results from .sup.1H NMR of purified
C.sub.12-C.sub.14 mcl-PHA.
[0038] FIG. 5B shows results from .sup.13C NMR of purified
C.sub.12-C.sub.14 mcl-PHA.
[0039] FIG. 6 shows PHA content in phasin-expressing E. coli
strains relative to base strains. The concentration of 3-OH-fatty
acid methyl esters derived from SA01 E. coli strains comprising
various plasmids is presented relative to the concentration in SA01
E. coli strains comprising the pDA-JAC and pBTrck plasmids. pMSB6
and pBTrck are medium and low copy vectors, respectively, harboring
IPTG inducible TRC promoters operably linked to no genes. Vector
pDA-JAC is a variant of pMSB6 harboring phaJ, acs, and phaC under
the control of the TRC promoter. Vector pPhaF is a variant of
pBTrck harboring gene PP.sub.--5007 (UniProtKB database), which
encodes a putative phasin having homology to phaF. Vector pPhal is
a variant of pBTrck harboring gene PP.sub.--5008 (UniProtKB
database), which encodes a putative phasin having homology to phal.
Note: E. coli SA01 produces small amounts of hydroxylated C14 fatty
acids (components of lipid A) that are also picked up in the PHA
extraction/derivatization. The data show that expression of phasins
in engineered mcl-PHA-producing E. coli increases PHA content
relative to base strains.
DETAILED DESCRIPTION OF THE INVENTION
[0040] The following abbreviations are used herein: [0041]
(mcl)-PHA--(medium-chain-length)-polyhydroxyalkanoate; [0042]
Acyl-carrier protein--ACP; [0043] BTE--California Bay Laurel
(Umbellularia californica) Thioesterase; [0044] CDW--Cell Dry
Weight; [0045] CoA--Coenzyme A; [0046] DO.sub.2--Dissolved oxygen;
[0047] EC--Enzyme Commission [0048] ECGSC--Escherichia coli Genetic
Stock Center--Yale University; [0049] FAME--Fatty Acid Methyl
Ester; [0050] GC/MS--Gas Chromatography Mass Spectrometry; [0051]
LB--Lysogeny Broth; [0052] PBS--Phosphate Buffered Saline; and
[0053] PCR--Polymerase Chain Reaction.
[0054] The present invention is directed to cells and methods for
producing polyhydroxyalkanoates having a defined monomeric
composition at a high yield from an unrelated carbon source. The
invention involves genetically modifying cells to feed carbon
substrates having a defined carbon length into the early steps of
the .beta.-oxidation pathway and then diverting the substrates
toward polyhydroxyalkanoate synthesis by shutting down or reducing
the efficiency of downstream steps in the .beta.-oxidation
pathway.
[0055] One aspect of the invention is a recombinant (i.e.,
genetically modified) cell that is capable of producing
polyhydroxyalkanoate. The cell of the present invention may be any
type of cell that is capable of producing polyhydroxyalkanoate,
either naturally or by virtue of genetic engineering. Examples of
suitable cells include but are not limited to bacterial cells,
yeast cells, fungal cells, insect cells, mammalian cells, and plant
cells. Examples of suitable bacterial cells include gram-positive
bacteria such as strains of Bacillus, (e.g., B. brevis or B.
subtilis), Pseudomonas, or Streptomyces, or gram-negative bacteria,
such as strains of E. coli or Aeromonas hydrophila. Particularly
desirable cells for expression in this regard include bacteria that
do not produce lipopolysaccharide and are endotoxin free. Examples
of suitable yeast cells include strains of Saccharomyces, such as
S. cerevisiae; Schizosaccharomyces; Kluyveromyces; Pichia, such as
P. pastoris or P. methlanolica; Hansenula, such as H. Polymorpha;
Yarrowia; or Candida. Examples of suitable filamentous fungal cells
include strains of Aspergillus, e.g., A. oryzae, A. niger, or A.
nidulans; Fusarium or Trichoderma. Examples of suitable insect
cells include a Lepidoptora cell line, such as Spodoptera
frugiperda (Sf9 or Sf21) or Trichoplusioa ni cells ("HIGH
FIVE"-brand insect cells, Invitrogen, Carlsbad, Calif.) (U.S. Pat.
No. 5,077,214). Examples of suitable mammalian cells include
Chinese hamster ovary (CHO) cell lines, e.g., CHO-K1 (ATCC CCL-61);
green monkey cell lines, e.g., COS-1 (ATCC CRL-1650) and COS-7
(ATCC CRL-1651); mouse cells, e.g., NS/O; baby hamster kidney (BHK)
cell lines, e.g., ATCC CRL-1632 or ATCC CCL-10; and human cells,
e.g., HEK 293 (ATCC CRL-1573). Examples of suitable plant cells
include those of oilseed crops, including rapeseed, canola,
sunflower, soybean, cottonseed, and safflower plants, and cells
from other plants such as Arabidopsis thaliana. Some of the
foregoing cell types are capable of naturally producing
polyhydroxyalkanoate, such as certain microorganisms. The other
cell types are capable of producing polyhydroxyalkanoate by being
genetically modified to express a PHA synthase or other enzymes.
See, e.g., U.S. Pat. No. 5,480,794 to Peoples et al. and Zhang et
al. Applied and Environmental Microbiology, 2006, 72(1):536-543,
which are incorporated by reference in their entirety. Preferred
cells are microorganisms, such as E. coli.
[0056] The recombinant cell of the invention preferably has one or
more genes in the f3-oxidation pathway functionally deleted to
inhibit consumption of substrates for polyhydroxyalkanoate
production. "Functional deletion" or its grammatical equivalents
refers to any modification to a microorganism that ablates,
reduces, inhibits, or otherwise disrupts production of a gene
product, renders the gene product non-functional, or otherwise
reduces or ablates the gene product's activity. "Gene product"
refers to a protein or polypeptide encoded and produced by a
particular gene. In some versions of the invention, functionally
deleting a gene product or homolog thereof means that the gene is
mutated to an extent that corresponding gene product is not
produced at all.
[0057] One of ordinary skill in the art will appreciate that there
are many well-known ways to functionally delete a gene product. For
example, functional deletion can be accomplished by introducing one
or more genetic modifications. As used herein, "genetic
modifications" refer to any differences in the nucleic acid
composition of a cell, whether in the cell's native chromosome or
in endogenous or exogenous non-chromosomal plasmids harbored within
the cell. Examples of genetic modifications that may result in a
functionally deleted gene product include but are not limited to
mutations, partial or complete deletions, insertions, or other
variations to a coding sequence or a sequence controlling the
transcription or translation of a coding sequence; placing a coding
sequence under the control of a less active promoter; and
expressing ribozymes or antisense sequences that target the mRNA of
the gene of interest, etc. In some versions, a gene or coding
sequence can be replaced with a selection marker or screenable
marker. Various methods for introducing the genetic modifications
described above are well known in the art and include homologous
recombination, among other mechanisms. See, e.g., Green et al.,
Molecular Cloning: A laboratory manual, 4.sup.th ed., Cold Spring
Harbor Laboratory Press (2012) and Sambrook et al., Molecular
Cloning: A Laboratory Manual, 3.sup.rd ed., Cold Spring Harbor
Laboratory Press (2001). Various other genetic modifications that
functionally delete a gene product are described in the examples
below. Functional deletion can also be accomplished by inhibiting
the activity of the gene product, for example, by chemically
inhibiting a gene product with a small-molecule inhibitor, by
expressing a protein that interferes with the activity of the gene
product, or by other means.
[0058] In certain versions of the invention, the functionally
deleted gene product may have less than about 95%, less than about
90%, less than about 85%, less than about 80%, less than about 75%,
less than about 70%, less than about 65%, less than about 60%, less
than about 55%, less than about 50%, less than about 45%, less than
about 40%, less than about 35%, less than about 30%, less than
about 25%, less than about 20%, less than about 15%, less than
about 10%, less than about 5%, less than about 1%, or about 0% of
the activity of the non-functionally deleted gene product.
[0059] In certain versions of the invention, a cell with a
functionally deleted gene product may have less than about 95%,
less than about 90%, less than about 85%, less than about 80%, less
than about 75%, less than about 70%, less than about 65%, less than
about 60%, less than about 55%, less than about 50%, less than
about 45%, less than about 40%, less than about 35%, less than
about 30%, less than about 25%, less than about 20%, less than
about 15%, less than about 10%, less than about 5%, less than about
1%, or about 0% of the activity of the gene product compared to a
cell with the non-functionally deleted gene product.
[0060] In certain versions of the invention, the functionally
deleted gene product may be expressed at an amount less than about
95%, less than about 90%, less than about 85%, less than about 80%,
less than about 75%, less than about 70%, less than about 65%, less
than about 60%, less than about 55%, less than about 50%, less than
about 45%, less than about 40%, less than about 35%, less than
about 30%, less than about 25%, less than about 20%, less than
about 15%, less than about 10%, less than about 5%, less than about
1%, or about 0% of the amount of the non-functionally deleted gene
product.
[0061] In certain versions of the invention, the functionally
deleted gene product may result from a genetic modification in
which at least 1, at least 2, at least 3, at least 4, at least 5,
at least 10, at least 20, at least 30, at least 40, at least 50, or
more nonsynonymous substitutions are present in the gene or coding
sequence of the gene product.
[0062] In certain versions of the invention, the functionally
deleted gene product may result from a genetic modification in
which at least 1, at least 2, at least 3, at least 4, at least 5,
at least 10, at least 20, at least 30, at least 40, at least 50, or
more bases are inserted in the gene or coding sequence of the gene
product.
[0063] In certain versions of the invention, the functionally
deleted gene product may result from a genetic modification in
which at least about 1%, at least about 5%, at least about 10%, at
least about 15%, at least about 20%, at least about 25%, at least
about 30%, at least about 35%, at least about 40%, at least about
50%, at least about 55%, at least about 60%, at least about 65%, at
least about 70%, at least about 75%, at least about 80%, at least
about 85%, at least about 90%, at least about 95%, or about 100% of
the gene product's gene or coding sequence is deleted or
mutated.
[0064] In certain versions of the invention, the functionally
deleted gene product may result from a genetic modification in
which at least about 1%, at least about 5%, at least about 10%, at
least about 15%, at least about 20%, at least about 25%, at least
about 30%, at least about 35%, at least about 40%, at least about
50%, at least about 55%, at least about 60%, at least about 65%, at
least about 70%, at least about 75%, at least about 80%, at least
about 85%, at least about 90%, at least about 95%, or about 100% of
a promoter driving expression of the gene product is deleted or
mutated.
[0065] In certain versions of the invention, the functionally
deleted gene product may result from a genetic modification in
which at least about 1%, at least about 5%, at least about 10%, at
least about 15%, at least about 20%, at least about 25%, at least
about 30%, at least about 35%, at least about 40%, at least about
50%, at least about 55%, at least about 60%, at least about 65%, at
least about 70%, at least about 75%, at least about 80%, at least
about 85%, at least about 90%, at least about 95%, or about 100% of
an enhancer controlling transcription of the gene product's gene is
deleted or mutated.
[0066] In certain versions of the invention, the functionally
deleted gene product may result from a genetic modification in
which at least about 1%, at least about 5%, at least about 10%, at
least about 15%, at least about 20%, at least about 25%, at least
about 30%, at least about 35%, at least about 40%, at least about
50%, at least about 55%, at least about 60%, at least about 65%, at
least about 70%, at least about 75%, at least about 80%, at least
about 85%, at least about 90%, at least about 95%, or about 100% of
a sequence controlling translation of gene product's mRNA is
deleted or mutated.
[0067] In certain versions of the invention, the decreased activity
or expression of the functionally deleted gene product is
determined with respect to the activity or expression of the gene
product in its unaltered state as found in nature. In certain
versions of the invention, the decreased activity or expression of
the functionally deleted gene product is determined with respect to
the activity or expression of the gene product in its form in a
corresponding cell. In certain versions, the genetic modifications
giving rise to a functionally deleted gene product are determined
with respect to the gene in its unaltered state as found in nature.
In certain versions, the genetic modifications giving rise to a
functionally deleted gene product are determined with respect to
the gene in its form in a corresponding cell. As used herein,
"corresponding cell" refers to a cell of the same species having
the same or substantially same genetic and proteomic composition as
a cell of the invention, with the exception of genetic and
proteomic differences resulting from the manipulations described
herein for the cells of the invention.
[0068] In some versions of the invention, a gene product of an
enoyl-CoA hydratase gene in the recombinant cell is functionally
deleted. Enoyl-CoA hydratases include enzymes classified under
Enzyme Commission (EC) number 4.2.1.17. Enoyl-CoA hydratases
catalyze the conversion of trans-2(or 3)-enoyl-CoA to
(3S)-3-hydroxyacyl-CoA in the .beta.-oxidation pathway. The term
"enoyl-CoA hydratase" used herein without an indication of
stereospecificity refers to the enzymes under EC 4.2.1.17 that
produce (3S)-3-hydroxyacyl-CoA. These enzymes are distinct from the
enzymes that produce (3R)-3-hydroxyacyl-CoA and are designated
under EC 4.2.1.119, which are referred to herein as "R-specific
enoyl-CoA hydratases." See below. Examples of enoyl-CoA hydratase
genes in bacteria include fadB (SEQ ID NO:1 (coding sequence) and
SEQ ID NO:2 (protein); GenBank NC.sub.--000913.2 at 4026805-4028994
(complement)) and fadJ (SEQ ID NO:3 (coding sequence) and SEQ ID
NO:3 (protein); GenBank NC.sub.--000913.2 at 2455037-2457181
(complement)). Examples of enoyl-CoA hydratase genes in yeast
include FOX2 (GenBank NC.sub.--001143 at 454352-457054
(complement)) or the enzyme encoded by Kyoto Encyclopedia of Genes
and Genomes (KEGG) (http://www.genome.jp/kegg/) entry number
NCU06488. An example of enoyl-CoA hydratase genes in filamentous
fungal cells includes the enzyme encoded by KEGG entry number
AN5916.2. An example of an enoyl-CoA hydratase gene in insect cells
is Mfe2 (GenBank NM.sub.--132881.2). Examples of enoyl-CoA
hydratase genes in mammalian cells include ECHS1 (GenBank
NM.sub.--004092.3), EHHADH (GenBank NM.sub.--001966.3), and HADHA
(GenBank NM.sub.--000182.4). Examples of enoyl-CoA hydratase genes
in plants include MFP2 (GenBank NM.sub.--111566.3) and AIM1
(GenBank NM.sub.--119045.4). Homologs of the above-mentioned
enoyl-CoA hydratase genes suitable for use in the present invention
can be determined by many known methods, one of which is described
below. In preferred versions of the invention, the enoyl-CoA
hydratase gene product that is functionally deleted has a sequence
comprising SEQ ID NO:2 or a sequence homologous thereto, SEQ ID
NO:4 or a sequence homologous thereto, or SEQ ID NO:2 and SEQ ID
NO:4 or sequences homologous thereto.
[0069] In some versions of the invention, a gene product of a
3-hydroxyacyl-CoA dehydrogenase gene in the recombinant cell is
functionally deleted. 3-Hydroxyacyl-CoA dehydrogenases include
enzymes classified under EC number 1.1.1.35. 3-Hydroxyacyl-CoA
dehydrogenases catalyze the conversion of (3S)-3-hydroxyacyl-CoA to
3-ketoacyl CoA in the .beta.-oxidation pathway. Examples of
3-hydroxyacyl-CoA dehydrogenase genes in bacteria include fadB (SEQ
ID NO:1 (coding sequence) and SEQ ID NO:2 (protein); GenBank
NC.sub.--000913.2 at 4026805-4028994 (complement)) and fadJ (SEQ ID
NO:3 (coding sequence) and SEQ ID NO:4 (protein); GenBank
NC.sub.--000913.2 at 2455037-2457181 (complement)). An example of a
3-hydroxyacyl-CoA dehydrogenase gene in yeast includes FOX2
(GenBank NC.sub.--001143 at 454352-457054 (complement)). An example
of a 3-hydroxyacyl-CoA dehydrogenase gene in filamentous fungal
cells includes the enzyme encoded by KEGG entry number AN7238.2. An
example of a 3-hydroxyacyl-CoA dehydrogenase gene in insect cells
is Mfe2 (GenBank NM.sub.--132881.2). Examples of 3-hydroxyacyl-CoA
dehydrogenase genes in mammalian cells include EHHADH (GenBank
NM.sub.--001966.3), HSD17B10 (GenBank NG.sub.--008153.1), HADH
(GenBank NM.sub.--001184705.2), and HSD17B4 (GenBank
NG.sub.--008182.1). Examples of 3-hydroxyacyl-CoA dehydrogenase
genes in plants include MFP2 (GenBank NM.sub.--111566.3) and AIM1
(GenBank NM.sub.--119045.4). Homologs of the above-mentioned
3-hydroxyacyl-CoA dehydrogenase genes suitable for use in the
present invention can be determined by many known methods, one of
which is described below. In preferred versions of the invention,
the 3-hydroxyacyl-CoA dehydrogenase gene product that is
functionally deleted has a sequence comprising SEQ ID NO:2 or a
sequence homologous thereto, SEQ ID NO:4 or a sequence homologous
thereto, or SEQ ID NO:2 and SEQ ID NO:4 or sequences homologous
thereto.
[0070] In some versions of the invention, a gene product of a
3-ketoacyl-CoA thiolase gene in the recombinant cell is
functionally deleted. 3-Ketoacyl-CoA thiolases include enzymes
classified under EC number 2.3.1.16. 3-Ketoacyl-CoA thiolases
catalyze the conversion of 3-ketoacyl CoA to acetyl-CoA and a
shortened acyl-CoA species in the .beta.-oxidation pathway.
Examples of 3-ketoacyl-CoA thiolase genes in bacteria include fadA
(SEQ ID NO:5 (coding sequence) and SEQ ID NO:6 (protein); GenBank
NC.sub.--000913.2 at 4025632-4026795 (complement)) and fadI (SEQ ID
NO:7 (coding sequence) and SEQ ID NO:8 (protein); GenBank
NC.sub.--000913.2 at 2457181-2458491 (complement)). An example of a
3-ketoacyl-CoA thiolase gene in yeast includes FOX3 (GenBank
NM.sub.--001179508.1). Examples of 3-ketoacyl-CoA thiolase genes in
filamentous fungal cells include the enzymes encoded by KEGG entry
numbers AN5646.2 and AN5698.2. An example of a 3-ketoacyl-CoA
thiolase gene in insect cells is gene yip2 (GenBank
NM.sub.--078804.3). Examples of 3-ketoacyl-CoA thiolase genes in
mammalian cells include ACAA1 (GenBank NR.sub.--024024.1), ACAA2
(GenBank NM.sub.--006111.2), and HADHB (GenBank NG.sub.--007294.1).
Examples of 3-ketoacyl-CoA thiolase genes in plants include PKT4
(GenBank NM.sub.--100351.4), PKT3 (GenBank NM.sub.--128874.3), and
PKT2 (GenBank NM.sub.--180826.3). Homologs of the above-mentioned
3-ketoacyl-CoA thiolase genes suitable for use in the present
invention can be determined by many known methods, one of which is
described below. In preferred versions of the invention,
3-ketoacyl-CoA thiolase gene product that is functionally deleted
has a sequence comprising SEQ ID NO:6 or a sequence homologous
thereto, SEQ ID NO:8 or a sequence homologous thereto, or SEQ ID
NO:6 and SEQ ID NO:8 or sequences homologous thereto.
[0071] Production of polyhydroxyalkanoates can be enhanced when the
.beta.-oxidation pathway is maximally shut down at a particular
step. When a cell has more than one enzyme catalyzing a step in the
.beta.-oxidation pathway, i.e., enoyl-CoA hydration,
(3S)-hydroxyacyl-CoA dehydrogenation, or ketoacyl-CoA thiolation,
it is preferred that more than one enzyme catalyzing that step is
functionally deleted. It is more preferred that all enzymes
catalyzing that step are functionally deleted. In the case of
bacteria, for example, it is preferred that products of both fadA
and fadI, both fadB, and fadJ, or all of fadA, fadB, fadI, and fadJ
are functionally deleted.
[0072] In some versions of the invention, one or more factors that
regulate expression of .beta.-oxidation genes in the cells are
functionally deleted. It is thought that such a modification to the
cells helps to enhance entry of carbon substrates into the
.beta.-oxidation pathway for synthesis of polyhydroxyalkanoates. In
preferred bacterial cells such as Escherichia coli, this is
accomplished by functionally deleting the product of fadR (SEQ ID
NO:9 (coding sequence) and SEQ ID NO:10 (protein); GenBank
NC.sub.--000913.2 at 1234161-1234880). FadR encodes a transcription
factor (fadR) that coordinately regulates the machinery required
for .beta.-oxidation and the expression of a key enzyme in fatty
acid biosynthesis. FadR works as a repressor that controls
transcription of the whole fad regulon, including fadA, fadB, fadD,
fadE, fadI, and fadJ. Binding of fadR is inhibited by fatty
acyl-CoA compounds, which de-represses expression of the genes in
the fad regulon. Functional deletion of fadR thereby upregulates
such genes as fadD and fadE to enhance entry of carbon substrates
through the initial steps of the .beta.-oxidation pathway (see FIG.
1). Regulatory proteins that control expression of .beta.-oxidation
genes in cells of other organisms are known in the art. The genes
encoding these proteins can be similarly functionally deleted to
enhance entry of carbon substrates through the initial steps of the
.beta.-oxidation pathway for synthesis of polyhydroxyalkanoates. In
preferred versions of the invention, the regulatory protein that is
functionally deleted has a sequence comprising SEQ ID NO:10 or a
sequence homologous thereto.
[0073] In a preferred bacterial cell of the invention, the cell
comprises a functional deletion of fadR gene product in addition to
functional deletion of products of fadA, fadI, fadB, fadJ, fadA and
fadI, fadB and fadJ, or fadA, fadB, fadI, and fadJ so that flux
through the initial steps .beta.-oxidation pathway is enhanced but
flux through the downstream steps (i.e., enoyl-CoA hydration,
(3S)-hydroxyacyl-CoA dehydrogenation, and/or ketoacyl-CoA
thiolation) is not.
[0074] In various versions of the invention, the cell is
genetically modified to comprise a recombinant gene. In most cases,
the recombinant gene is configured to be expressed or overexpressed
in the cell. If a cell endogenously comprises a particular gene,
the gene may be modified to exchange or optimize promoters,
exchange or optimize enhancers, or exchange or optimize any other
genetic element to result in increased expression of the gene.
Alternatively, one or more additional copies of the gene or coding
sequence thereof may be introduced to the cell for enhanced
expression of the gene product. If a cell does not endogenously
comprise a particular gene, the gene or coding sequence thereof may
be introduced to the cell for expression of the gene product. The
gene or coding sequence may be incorporated into the genome of the
cell or may be contained on an extra-chromosomal plasmid. The gene
or coding sequence may be introduced to the cell individually or
may be included on an operon. Techniques for genetic manipulation
are described in further detail below.
[0075] In some versions of the invention, the cells are genetically
modified to express or overexpress a recombinant acyl-CoA
synthetase gene. This is thought to constitute a mechanism of
modifying cells to enhance entry of carbon substrates into the
.beta.-oxidation pathway. Suitable acyl-CoA synthetases include
enzymes classified under the EC 6.2.1.-, such as EC 6.2.1.3.
Acyl-CoA synthetases catalyze the conversion of free fatty acids,
coenzyme A, and ATP to fatty acyl CoAs plus AMP (Black et al. 1992,
J. Biol. Chem. 267:25513-25520). Examples of suitable genes for
acyl CoA synthetases include fadD (SEQ ID NO:11 (coding sequence)
and SEQ ID NO:12 (protein); GenBank NC.sub.--000913.2 at
1886085-1887770 (complement)) from E. coli (Black et al. 1992, J.
Biol. Chem. 267:25513-25520), alkK from Pseudomonas oleovorans
(GenBank AJ245436.1 at 13182-14822) (van Beilen et al. 1992,
Molecular Microbiology 6:3121-3136), Pfacsl from Plasmodium
falciparum (GenBank AF007828.2) (Matesanz et al. 1999, J. Mol.
Biol. 291:59-70), and PP.sub.--0763 (KEGG) from P. putida (SEQ ID
NO:13 (coding sequence) and SEQ ID NO:14 (protein)), described
herein. Methods and materials for identification of other suitable
acyl-CoA synthetases are described in U.S. Pat. No. 7,786,355.
Homologs of the above-mentioned acyl-CoA synthetase genes suitable
for use in the present invention can be determined by many known
methods, one of which is described below. In preferred versions of
the invention, the cells express or overexpress an acyl-CoA
synthetase gene product that has a sequence comprising SEQ ID NO:12
or a sequence homologous thereto, SEQ ID NO:14 or a sequence
homologous thereto, or SEQ ID NO:12 and SEQ ID NO:14 or sequences
homologous thereto.
[0076] In some versions of the invention, the cells are genetically
modified to express or overexpress a recombinant R-specific
enoyl-CoA hydratase gene. R-specific enoyl-CoA hydratase genes
include enzymes classified under EC 4.2.1.119. R-specific enoyl-CoA
hydratase genes catalyze the conversion of trans-2(or 3)-enoyl-CoA
to (3R)-3-hydroxyacyl-CoA. As described above, the term "R-specific
enoyl-CoA hydratase," refers only to enzymes which produce
(3R)-3-hydroxyacyl-CoA and are distinct from the enzymes referred
to herein as "enoyl-CoA hydratase," which produce
(3S)-3-hydroxyacyl-CoA and are classified under EC 4.2.1.17.
Examples of suitable R-specific enoyl-CoA hydratases include any of
the various phaJ genes in such microorganisms as Aeromonas spp.,
including A. caviae, Pseudomonas aeruginosa, Ralstonia eutropha,
among others. See the following Examples for methods for amplifying
PHA genes phaJ1-4, the sequences of which can be readily obtained
using methods known in the art. Homologs of the above-mentioned
R-specific enoyl-CoA hydratase genes suitable for the use in the
present invention can be determined by many known methods, one of
which is described below.
[0077] In some versions of the invention, the cells are genetically
modified to express or overexpress a recombinant PHA polymerase
gene. PHA polymerase genes include enzymes classified under EC
2.3.1.-. PHA polymerase genes catalyze the conversion of
(3R)-3-hydroxyacyl-CoA monomers into polyhydroxyalkanoate polymers.
Examples of suitable PHA polymerases include any of the various
phaC or phbC genes in such microorganisms as Pseudomonas
aeruginosa, among others. See the following Examples for methods
for amplifying PHA genes phaC1-2, the sequences of which can be
readily obtained using methods known in the art. See also U.S. Pat.
No. 5,250,430 and Tsuge et al. 2003, International Journal of
Biological Macromolecules. 31:195-205. Homologs of the
above-mentioned PHA polymerase genes suitable for the use in the
present invention can be determined by many known methods, one of
which is described below.
[0078] For high production of mcl-PHA containing high yields of
C.sub.12 monomer units, it is preferred that the cell expresses or
overexpresses a combination of phaJ3 (SEQ ID NO:15 (coding
sequence) and SEQ ID NO:16 (protein)) and phaC2 (SEQ ID NO:17
(coding sequence) and SEQ ID NO:18 (protein)), as this combination
unexpectedly results in a high PHA content with a high C.sub.12
composition. See, e.g., the examples, particularly at Table 2.
Accordingly, cells in preferred versions of the invention express
or overexpress gene products having a sequence comprising SEQ ID
NO:16 or a sequence homologous thereto, SEQ ID NO:18 or a sequence
homologous thereto, or SEQ ID NO:16 and SEQ ID NO:18 or sequences
homologous thereto.
[0079] In some versions of the invention, the cells are genetically
modified to express or overexpress a recombinant thioesterase gene.
Thioesterases include enzymes classified into EC 3.1.2.1 through EC
3.1.2.27 based on their activities on different substrates, with
many remaining unclassified (EC 3.1.2.-). Thioesterases hydrolyze
thioester bonds between acyl chains and CoA or on acyl chains and
ACP. These enzymes terminate fatty acid synthesis by removing the
CoA or ACP from the acyl chain.
[0080] Expression or overexpression of a recombinant thioesterase
gene can be used to engineer to produce a homogeneous population of
fatty acid products to feed into the .beta.-oxidation and
polyhydroxyalkanoate synthesis pathways, and thereby produce
polyhydroxyalkanoates having a defined side chain length. To
engineer a cell for the production of a homogeneous population of
fatty acid products, one or more thioesterases with a specificity
for a particular carbon chain length or chain lengths can be
expressed. For example, any of the thioesterases shown in the
following table can be expressed individually or in combination to
increase production of fatty acid products having specific chain
lengths.
TABLE-US-00001 Thioesterases. Gen Bank Preferential Accession
Source product Number Organism Gene produced AAC73596 E. coli tesA
without C.sub.8-C.sub.18 leader sequence Q41635; Umbellularia fatB
C.sub.12:0 V17097; californica M94159 Q39513 Cuphea fatB2
C.sub.8:0-C.sub.10:0 hookeriana AAC49269 Cuphea fatB3
C.sub.14:0-C.sub.16:0 hookeriana Q39473 Cinnamonum fatB C.sub.14:0
camphorum CAA85388 Arabidopsis fatB[M141T]* C.sub.16:1 thaliana NP
189147; Arabidopsis fatA C.sub.18:1 NP 193041 thaliana CAC39106
Bradyrhiizobium fatA C.sub.18:1 japonicum AAC72883 Cuphea fatA
C.sub.18:1 hookeriana *Mayer et al., BMC Plant Biology 7: 1-11,
2007.
[0081] Other thioesterases that can be expressed or overexpressed
in the cell include any of the many acyl-acyl carrier protein
thioesterases from Streptococcus pyogenes, including any having
GenBank Accession Numbers AAZ51384.1, AAX71858.1, AAT86926.1,
YP.sub.--280213.1, YP.sub.--060109.1, YP.sub.--006932842.1,
YP.sub.--005411534.1, AFC68003.1, AFC66139.1, YP.sub.--006071945.1,
YP.sub.--600436.1, AEQ24391.1 and ABF37868.1; a palmitoyl-acyl
carrier protein thioesterase from Ricinus communis, such as those
having GenBank Accession Numbers EEF47013.1, XP.sub.--002515564.1,
EEF51750.1, XP.sub.--002511148.1, and EEF36100.1; a myristoyl-acyl
carrier protein thioesterase from Ricinus communis, such as those
having GenBank Accession Numbers EEF44689.1 and
XP.sub.--002517525.1; an oleoyl-acyl carrier protein thioesterase
from Ricinus communis, such as those having GenBank Accession
Numbers EEF29646.1 and XP.sub.--002532744.1; an acyl-acyl carrier
protein thioesterase from Ricinus communis, such as that having
GenBank Accession Number ABV54795.1; an acyl-acyl carrier protein
thioesterase from Jatropha curcus, such as that described in Zhang,
X. et al. (2011) Metab. Eng. 13, 713-722; an FabD from Streptomyces
avermitilis, such as that having GenBank Accession Number
NP.sub.--826965.1; a FadM acyl-CoA thioesterase from E. coli, such
as that having GenBank Accession Number NP.sub.--414977.1; a TesB
thioesterase II (acyl-CoA thioesterase), such as those having
GenBank Accession Numbers ZP.sub.--12508749.1, EGT66607.1,
ZP.sub.--03035215.1, and EDV65664.1; and a fatB-type thioesterase
specific for C18:1 and C18:0 derived from Madhuca latifolia, such
as that having the GenBank Accession Number AY835985. These and
additional suitable thioesterases that can be expressed or
overexpressed in the cell are described in U.S. 2011/0165637 to
Pfleger et al.; Lu, X. et al. (2008) Metab. Eng. 10, 333-339; Liu,
T. et al. (2010) Metab. Eng. 12, 378-386; Steen, E. J. et al.
(2010) Nature 463, 559-562; Lennen, R. M. et al. (2010) Biotechnol.
Bioeng. 106, 193-202; Lennen, R. M. et al. (2011) Appl. Environ.
Microbiol. 77, 8114-8128; Youngquist, J. T. et al. (2012)
Biotechnol. Bioeng. 109, 1518-1527; Jeon, E. et al. (2011) Enzyme
Microb. Technol. 49, 44-51; Li, M. et al. (2012) Metab. Eng. 14,
380-387; Zhang, X. et al. (2012) Biotechnol. Prog. 28, 60-65;
Zhang, X. et al. (2011) Metab. Eng. 13, 713-722; Liu, H. et al.
(2012) Microb. Cell Fact. 11, 41; Yu, X. et al. (2011) Proc. Natl.
Acad. Sci. U.S.A. 108, 18643-18648; Dellomonaco, C. et al. (2011)
Nature 476, 355-359; Zhang, F. et al. (2012) Nat. Biotechnol. 30,
354-359; and Lennen et al. (2012) Trends in Biotechnology 30(12),
659-667. Yet other suitable thioesterases can be found in the
ThYme: Thioester-active Enzymes database at
http://www.enzyme.chirc.iastate.edu/. Homologs of the thioesterases
described herein suitable for the use in the present invention can
be determined by many known methods, one of which is described
below.
[0082] In some versions, one or more endogenous thioesterases
having a specificity for carbon chain lengths other than the
desired product's carbon chain length can be functionally deleted.
For example, C10 fatty acid products can be produced by attenuating
a thioesterase specific for C18 (for example, accession numbers
AAC73596 and POADA1), and expressing a thioesterase specific for
C10 (for example, accession number Q39513). This results in a
relatively homogeneous population of fatty acid products that have
a carbon chain length of 10. In another example, C14 fatty acid
products can be produced by attenuating endogenous thioesterases
that produce non-C14 fatty acids and expressing the thioesterase
with accession number Q39473, which uses C14-acyl carrier protein
(ACP) as a substrate. In yet another example, C12 fatty acid
products can be produced by expressing thioesterases that use
C12-ACP as a substrate (for example, accession number Q41635) and
attenuating thioesterases that produce non-C12 fatty acids.
[0083] In a preferred version of the invention, the cell comprises
a gene expressing a codon-optimized thioesterase derived from
California Bay Laurel (Umbellularia californica) thioesterase (BTE)
having the following nucleic acid coding sequence (SEQ ID NO:19)
and amino acid sequence (SEQ ID NO:20):
TABLE-US-00002 cccgggagga ggattataaa atg act cta gag tgg aaa ccg
aaa cca aaa ctg 53 Met Thr Leu Glu Trp Lys Pro Lys Pro Lys Leu 1 5
10 cct caa ctg ctg gat gat cac ttc ggt ctg cac ggt ctg gtg ttt cgt
101 Pro Gln Leu Leu Asp Asp His Phe Gly Leu His Gly Leu Val Phe Arg
15 20 25 cgt act ttc gca att cgt tct tat gaa gtg ggt cca gat cgt
tct acc 149 Arg Thr Phe Ala Ile Arg Ser Tyr Glu Val Gly Pro Asp Arg
Ser Thr 30 35 40 tcc atc ctg gcc gtc atg aac cac atg cag gaa gcc
acc ctg aat cac 197 Ser Ile Leu Ala Val Met Asn His Met Gln Glu Ala
Thr Leu Asn His 45 50 55 gcg aaa tct gtt ggt atc ctg ggt gat ggt
ttc ggc act act ctg gaa 245 Ala Lys Ser Val Gly Ile Leu Gly Asp Gly
Phe Gly Thr Thr Leu Glu 60 65 70 75 atg tct aaa cgt gac ctg atg tgg
gta gtg cgt cgc acc cac gta gca 293 Met Ser Lys Arg Asp Leu Met Trp
Val Val Arg Arg Thr His Val Ala 80 85 90 gta gag cgc tac cct act
tgg ggt gac act gtg gaa gtc gag tgt tgg 341 Val Glu Arg Tyr Pro Thr
Trp Gly Asp Thr Val Glu Val Glu Cys Trp 95 100 105 att ggc gcg tcc
ggt aac aat ggt atg cgt cgc gat ttt ctg gtc cgt 389 Ile Gly Ala Ser
Gly Asn Asn Gly Met Arg Arg Asp Phe Leu Val Arg 110 115 120 gac tgt
aaa acg ggc gaa atc ctg acg cgt tgc acc tcc ctg agc gtt 437 Asp Cys
Lys Thr Gly Glu Ile Leu Thr Arg Cys Thr Ser Leu Ser Val 125 130 135
ctg atg aac acc cgc act cgt cgc ctg tct acc atc ccg gac gaa gtg 485
Leu Met Asn Thr Arg Thr Arg Arg Leu Ser Thr Ile Pro Asp Glu Val 140
145 150 155 cgc ggt gag atc ggt cct gct ttc atc gat aac gtg gca gtt
aaa gac 533 Arg Gly Glu Ile Gly Pro Ala Phe Ile Asp Asn Val Ala Val
Lys Asp 160 165 170 gac gaa atc aag aaa ctg caa aaa ctg aac gac tcc
acc gcg gac tac 581 Asp Glu Ile Lys Lys Leu Gln Lys Leu Asn Asp Ser
Thr Ala Asp Tyr 175 180 185 atc cag ggc ggt ctg act ccg cgc tgg aac
gac ctg gat gtt aat cag 629 Ile Gln Gly Gly Leu Thr Pro Arg Trp Asn
Asp Leu Asp Val Asn Gln 190 195 200 cat gtg aac aac ctg aaa tac gtt
gct tgg gtc ttc gag act gtg ccg 677 His Val Asn Asn Leu Lys Tyr Val
Ala Trp Val Phe Glu Thr Val Pro 205 210 215 gac agc att ttc gaa agc
cat cac att tcc tct ttt act ctg gag tac 725 Asp Ser Ile Phe Glu Ser
His His Ile Ser Ser Phe Thr Leu Glu Tyr 220 225 230 235 cgt cgc gaa
tgt act cgc gac tcc gtt ctg cgc agc ctg acc acc gta 773 Arg Arg Glu
Cys Thr Arg Asp Ser Val Leu Arg Ser Leu Thr Thr Val 240 245 250 agc
ggc ggt tct agc gag gca ggt ctg gtc tgc gac cat ctg ctg caa 821 Ser
Gly Gly Ser Ser Glu Ala Gly Leu Val Cys Asp His Leu Leu Gln 255 260
265 ctg gaa ggc ggc tcc gaa gtc ctg cgt gcg cgt acg gag tgg cgt cca
869 Leu Glu Gly Gly Ser Glu Val Leu Arg Ala Arg Thr Glu Trp Arg Pro
270 275 280 aag ctg acg gat tct ttc cgc ggc atc tcc gta att ccg gcg
gaa cct 917 Lys Leu Thr Asp Ser Phe Arg Gly Ile Ser Val Ile Pro Ala
Glu Pro 285 290 295
[0084] See, e.g., U.S. 2011/0165637 to Pfleger et al. Expression of
BTE in the cell generates fatty acid substrates in the cell
suitable for production of mcl-PHAs. Cells in preferred versions of
the invention express or overexpress a gene product having a
sequence comprising SEQ ID NO:20 or a sequence homologous
thereto.
[0085] In some versions of the invention, the cells are genetically
modified to express or overexpress a recombinant phasein gene.
Examples of suitable phasins include the phasins from Pseudomonas
putida KT2440 annotated as "Polyhydroxyalkanoate granule-associated
proteins" on the UniProKB database (http://www.uniprot.org/) with
locus tags of PP.sub.--5008 (SEQ ID NO:21 (coding sequence) and SEQ
ID NO:22 (protein)) and PP.sub.--5007 (SEQ ID NO:23 (coding
sequence) and SEQ ID NO:24 (protein)). These phasins have a high
degree of homology to other phasin genes phal and phaF,
respectively. Homologs of the above-mentioned phasin genes suitable
for the use in the present invention can be determined by many
known methods, one of which is described below. Cells in preferred
versions of the invention express or overexpress gene products
having a sequence comprising SEQ ID NO:22 or a sequence homologous
thereto, SEQ ID NO:24 or a sequence homologous thereto, or SEQ ID
NO:22 and SEQ ID NO:24 or sequences homologous thereto.
[0086] Polyhydroxyalkanoates can be produced with the cells
described herein by culturing the cells in the presence of a carbon
source. The carbon source preferably includes a carbohydrate or
non-lipid based carbon source, such as a fermentable sugar, a
short-chain organic acid, an amino acid, or other organic
molecules. Examples of suitable fermentable sugars include
adonitol, arabinose, arabitol, ascorbic acid, chitin, cellubiose,
dulcitol, erythrulose, fructose, fucose, galactose, glucose,
gluconate, inositol, lactose, lactulose, lyxose, maltitol, maltose,
maltotriose, mannitol, mannose, melezitose, melibiose, palatinose,
pentaerythritol, raffinose, rhamnose, ribose, sorbitol, sorbose,
starch, sucrose, trehalose, xylitol, xylose, and hydrates thereof.
Examples of short-chain organic acids include acetate, propionate,
lactate, pyruvate, levulinate, and succinate. Examples of amino
acids include histidine, alanine, isoleucine, arginine, leucine,
asparagine, lysine, aspartic acid, methionine, cysteine,
phenylalanine, glutamic acid, threonine, glutamine, tryptophan,
glycine, valine, ornithine, proline, serine, and tyrosine.
[0087] The carbon sources may also include an exogenous supply of
fatty acids. However, in the preferred version of the invention,
the culturing is performed in a medium substantially devoid of a
fatty acid source, such as free fatty acids or fatty-acid
containing lipids, and/or exogenous lipids in general. In various
versions of the invention, the growth medium preferably includes no
more than about 1 g L.sup.-1 free fatty acid or salt thereof, no
more than about 0.5 g L.sup.-1 free fatty acid or salt thereof, no
more than about 0.25 g L.sup.-1 free fatty acid or salt thereof, no
more than about 0.1 g L.sup.-1 free fatty acid or salt thereof, no
more than about 0.05 g L.sup.-1 free fatty acid or salt thereof, no
more than about 0.01 g L.sup.-1 free fatty acid or salt thereof, no
more than about 0.005 g L.sup.-1 free fatty acid or salt thereof,
or no more than about 0.001 g L.sup.-1 free fatty acid or salt
thereof.
[0088] In a preferred version of the invention, the culturing is
performed in aerobic conditions. To maintain such aerobic
conditions, it is preferred that the DO.sub.2 content of the medium
does not decrease below about 35% saturation, about 40% saturation,
or about 50% saturation (Becker et al., 1997; Tseng et al.,
1996).
[0089] In various versions of the invention, the culturing is
performed until the cell reaches an amount of polyhydroxyalkanoate
of at least about 7.5% cell dry weight, at least about 10% cell dry
weight, at least about 15% cell dry weight, at least about 20% cell
dry weight, at least about 25% cell dry weight, at least about 30%
cell dry weight, at least about 35% cell dry weight, at least about
40% cell dry weight, at least about 45% cell dry weight, at least
about 50% cell dry weight, at least about 55% cell dry weight, at
least about 60% cell dry weight, at least about 65% cell dry
weight, at least about 70% cell dry weight, or at least about 75%
cell dry weight. Accordingly the cells of the invention are capable
of producing an amount of polyhydroxyalkanoate of at least about
7.5% cell dry weight, at least about 10% cell dry weight, at least
about 15% cell dry weight, at least about 20% cell dry weight, at
least about 25% cell dry weight, at least about 30% cell dry
weight, at least about 35% cell dry weight, at least about 40% cell
dry weight, at least about 45% cell dry weight, at least about 50%
cell dry weight, at least about 55% cell dry weight, at least about
60% cell dry weight, at least about 65% cell dry weight, at least
about 70% cell dry weight, or at least about 75% cell dry
weight.
[0090] In preferred versions of the invention, the cell produces
polyhydroxyalkanoate comprised of hydroxyalkanoate monomers,
wherein a large proportion of the hydroxyalkanoate monomers
comprise hydrocarbon chains comprising the same number of carbons.
The number of carbons may be 7, 8, 9, 10, 11, 12, 13, 14, 15, 16,
or 18 carbons. In various versions, greater than about 50%, about
55%, about 60%, about 65%, about 70%, about 75%, about 80%, or
about 85% of the hydroxyalkanoate monomers comprise hydrocarbon
chains comprising same number of carbons. The cell preferably
produces such polyhydroxyalkanoate in the absence of exogenously
supplied fatty acids.
[0091] The cells of the invention may be genetically altered to
functionally delete, express, or overexpress homologs of any of the
specific genes or gene products explicitly described herein.
Proteins and/or protein sequences are "homologous" when they are
derived, naturally or artificially, from a common ancestral protein
or protein sequence. Similarly, nucleic acids and/or nucleic acid
sequences are homologous when they are derived, naturally or
artificially, from a common ancestral nucleic acid or nucleic acid
sequence. Nucleic acid or gene product (amino acid) sequences of
any known gene, including the genes or gene products described
herein, can be determined by searching any sequence databases known
the art using the gene name or accession number as a search term.
Common sequence databases include GenBank
(http://wwwncbi.nim.nih.gov/genbank/), ExPASy (http://expasy.org/),
KEGG (www.genome.jp/kegg/), among others. Homology is generally
inferred from sequence similarity between two or more nucleic acids
or proteins (or sequences thereof). The precise percentage of
similarity between sequences that is useful in establishing
homology varies with the nucleic acid and protein at issue, but as
little as 25% sequence similarity (e.g., identity) over 50, 100,
150 or more residues (nucleotides or amino acids) is routinely used
to establish homology (e.g., over the full length of the two
sequences to be compared). Higher levels of sequence similarity
(e.g., identity), e.g., 30%, 35% 40%, 45% 50%, 55%, 60%, 65%, 70%,
75%, 80%, 85%, 90%, 95%, or 99% or more, can also be used to
establish homology. Accordingly, homologs of the genes or gene
products described herein include genes or gene products having at
least about 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%,
85%, 90%, 95%, or 99% identity to the genes or gene products
described herein. Methods for determining sequence similarity
percentages (e.g., BLASTP and BLASTN using default parameters) are
described herein and are generally available. The homologous
proteins should demonstrate comparable activities and, if an
enzyme, participate in the same or analogous pathways. "Orthologs"
are genes in different species that evolved from a common ancestral
gene by speciation. Normally, orthologs retain the same or similar
function in the course of evolution. As used herein "orthologs" are
included in the term "homologs".
[0092] For sequence comparison and homology determination, one
sequence typically acts as a reference sequence to which test
sequences are compared. When using a sequence comparison algorithm,
test and reference sequences are input into a computer, subsequence
coordinates are designated, if necessary, and sequence algorithm
program parameters are designated. The sequence comparison
algorithm then calculates the percent sequence identity for the
test sequence(s) relative to the reference sequence based on the
designated program parameters. A typical reference sequence of the
invention is a nucleic acid or amino acid sequence corresponding to
acsA or other genes or products described herein.
[0093] Optimal alignment of sequences for comparison can be
conducted, e.g., by the local homology algorithm of Smith &
Waterman, Adv. Appl. Math. 2:482 (1981), by the homology alignment
algorithm of Needleman & Wunsch, J. Mol. Biol. 48:443 (1970),
by the search for similarity method of Pearson & Lipman, Proc.
Nat'l. Acad. Sci. USA 85:2444 (1988), by computerized
implementations of these algorithms (GAP, BESTFIT, FASTA, and
TFASTA in the Wisconsin Genetics Software Package, Genetics
Computer Group, 575 Science Dr., Madison, Wis.), or by visual
inspection (see Current Protocols in Molecular Biology, F. M.
Ausubel et al., eds., Current Protocols, a joint venture between
Greene Publishing Associates, Inc. and John Wiley & Sons, Inc.,
(supplemented through 2008)).
[0094] One example of an algorithm that is suitable for determining
percent sequence identity and sequence similarity for purposes of
defining homologs is the BLAST algorithm, which is described in
Altschul et al., J. Mol. Biol. 215:403-410 (1990). Software for
performing BLAST analyses is publicly available through the
National Center for Biotechnology Information. This algorithm
involves first identifying high scoring sequence pairs (HSPs) by
identifying short words of length W in the query sequence, which
either match or satisfy some positive-valued threshold score T when
aligned with a word of the same length in a database sequence. T is
referred to as the neighborhood word score threshold (Altschul et
al., supra). These initial neighborhood word hits act as seeds for
initiating searches to find longer HSPs containing them. The word
hits are then extended in both directions along each sequence for
as far as the cumulative alignment score can be increased.
Cumulative scores are calculated using, for nucleotide sequences,
the parameters M (reward score for a pair of matching residues;
always>0) and N (penalty score for mismatching residues;
always<0). For amino acid sequences, a scoring matrix is used to
calculate the cumulative score. Extension of the word hits in each
direction are halted when: the cumulative alignment score falls off
by the quantity X from its maximum achieved value; the cumulative
score goes to zero or below, due to the accumulation of one or more
negative-scoring residue alignments; or the end of either sequence
is reached. The BLAST algorithm parameters W, T, and X determine
the sensitivity and speed of the alignment. The BLASTN program (for
nucleotide sequences) uses as defaults a wordlength (W) of 11, an
expectation (E) of 10, a cutoff of 100, M=5, N=-4, and a comparison
of both strands. For amino acid sequences, the BLASTP program uses
as defaults a wordlength (W) of 3, an expectation (E) of 10, and
the BLOSUM62 scoring matrix (see Henikoff & Henikoff (1989)
Proc. Natl. Acad. Sci. USA 89:10915).
[0095] In addition to calculating percent sequence identity, the
BLAST algorithm also performs a statistical analysis of the
similarity between two sequences (see, e.g., Karlin & Altschul,
Proc. Natl. Acad. Sci. USA 90:5873-5787 (1993)). One measure of
similarity provided by the BLAST algorithm is the smallest sum
probability (P(N)), which provides an indication of the probability
by which a match between two nucleotide or amino acid sequences
would occur by chance. For example, a nucleic acid is considered
similar to a reference sequence if the smallest sum probability in
a comparison of the test nucleic acid to the reference nucleic acid
is less than about 0.1, more preferably less than about 0.01, and
most preferably less than about 0.001. The above-described
techniques are useful in identifying homologous sequences for use
in the methods described herein.
[0096] The terms "identical" or "percent identity", in the context
of two or more nucleic acid or polypeptide sequences, refer to two
or more sequences or subsequences that are the same or have a
specified percentage of amino acid residues or nucleotides that are
the same, when compared and aligned for maximum correspondence, as
measured using one of the sequence comparison algorithms described
above (or other algorithms available to persons of skill) or by
visual inspection.
[0097] The phrase "substantially identical" in the context of two
nucleic acids or polypeptides refers to two or more sequences or
subsequences that have at least about 60%, about 65%, about 70%,
about 75%, about 80%, about 85%, about 90, about 95%, about 98%, or
about 99% or more nucleotide or amino acid residue identity, when
compared and aligned for maximum correspondence, as measured using
a sequence comparison algorithm or by visual inspection. Such
"substantially identical" sequences are typically considered to be
"homologous", without reference to actual ancestry. Preferably, the
"substantial identity" exists over a region of the sequences that
is at least about 50 residues in length, more preferably over a
region of at least about 100 residues, and most preferably, the
sequences are substantially identical over at least about 150
residues, at least about 250 residues, or over the full length of
the two sequences to be compared.
[0098] Terms used herein pertaining to genetic manipulation are
defined as follows.
[0099] Accession numbers: The accession numbers throughout this
description are derived from the NCBI database (National Center for
Biotechnology Information, i.e., "GenBank"), maintained by the
National Institute of Health, USA, or the KEGG (Kyoto Encyclopedia
of Genes and Genomics) database, maintained by the Kyoto
Encyclopedia of Genes and Genomics and sponsored in part by the
University of Tokyo.
[0100] Deletion: The removal of one or more nucleotides from a
nucleic acid molecule or one or more amino acids from a protein,
the regions on either side being joined together.
[0101] Derived: When used with reference to a nucleic acid or
protein, "derived" means that the nucleic acid or polypeptide is
isolated from a described source or is at least 70%, 80%, 90%, 95%,
99%, or more identical to a nucleic acid or polypeptide included in
the described source.
[0102] Endogenous: As used herein with reference to a nucleic acid
molecule and a particular cell, "endogenous" refers to a nucleic
acid sequence or polypeptide that is in the cell and was not
introduced into the cell using recombinant engineering techniques.
For example, an endogenous gene is a gene that was present in a
cell when the cell was originally isolated from nature.
[0103] Exogenous: As used herein with reference to a nucleic acid
molecule or polypeptide in a particular cell, "exogenous" refers to
any nucleic acid molecule or polypeptide that does not originate
from that particular cell as found in nature. Thus, a
non-naturally-occurring nucleic acid molecule or protein is
considered to be exogenous to a cell once introduced into the cell.
A nucleic acid molecule or protein that is naturally-occurring also
can be exogenous to a particular cell. For example, an entire
coding sequence isolated from cell X is an exogenous nucleic acid
with respect to cell Y once that coding sequence is introduced into
cell Y, even if X and Y are the same cell type. The term
"heterologous" is used herein interchangeably with "exogenous."
[0104] Expression: The process by which a gene's coded information
is converted into the structures and functions of a cell, such as a
protein, transfer RNA, or ribosomal RNA. Expressed genes include
those that are transcribed into mRNA and then translated into
protein and those that are transcribed into RNA but not translated
into protein (for example, transfer and ribosomal RNAs).
[0105] Introduce: When used with reference to genetic material,
such as a nucleic acid, and a cell, "introduce" refers to the
delivery of the genetic material to the cell in a manner such that
the genetic material is capable of being expressed within the cell.
Introduction of genetic material includes both transformation and
transfection. Transformation encompasses techniques by which a
nucleic acid molecule can be introduced into cells such as
prokaryotic cells or non-animal eukaryotic cells. Transfection
encompasses techniques by which a nucleic acid molecule can be
introduced into cells such as animal cells. These techniques
include but are not limited to introduction of a nucleic acid via
conjugation, electroporation, lipofection, infection, and particle
gun acceleration.
[0106] Isolated: An "isolated" biological component (such as a
nucleic acid molecule, polypeptide, or cell) has been substantially
separated or purified away from other biological components in
which the component naturally occurs, such as other chromosomal and
extrachromosomal DNA and RNA and proteins. Nucleic acid molecules
and polypeptides that have been "isolated" include nucleic acid
molecules and polypeptides purified by standard purification
methods. The term also includes nucleic acid molecules and
polypeptides prepared by recombinant expression in a cell as well
as chemically synthesized nucleic acid molecules and polypeptides.
In one example, "isolated" refers to a naturally-occurring nucleic
acid molecule that is not immediately contiguous with both of the
sequences with which it is immediately contiguous (one on the 5'
end and one on the 3' end) in the naturally-occurring genome of the
organism from which it is derived.
[0107] Medium chain: When used with reference to medium chain fatty
acids or medium chain polyhydroxyalkanoates refers to a carbon
chain length of from 7 to 18 carbons, and such as a carbon chain
length of from 7 to 11 carbons.
[0108] Nucleic acid: Encompasses both RNA and DNA molecules
including, without limitation, cDNA, genomic DNA, and mRNA. Nucleic
acids also include synthetic nucleic acid molecules, such as those
that are chemically synthesized or recombinantly produced. The
nucleic acid can be double-stranded or single-stranded. Where
single-stranded, the nucleic acid molecule can be the sense strand,
the antisense strand, or both. In addition, the nucleic acid can be
circular or linear.
[0109] Operably linked: A first nucleic acid sequence is operably
linked with a second nucleic acid sequence when the first nucleic
acid sequence is placed in a functional relationship with the
second nucleic acid sequence. For instance, a promoter is operably
linked to a coding sequence if the promoter affects the
transcription or expression of the coding sequence. An origin of
replication is operably linked to a coding sequence if the origin
of replication controls the replication or copy number of the
nucleic acid in the cell. Operably linked nucleic acids may or may
not be contiguous.
[0110] Operon: Configurations of separate genes that are
transcribed in tandem as a single messenger RNA are denoted as
operons. Thus, a set of in-frame genes in close proximity under the
transcriptional regulation of a single promoter constitutes an
operon. Operons may be synthetically generated using the methods
described herein.
[0111] Overexpress: When a gene is caused to be transcribed at an
elevated rate compared to the endogenous or basal transcription
rate for that gene. In some examples, overexpression additionally
includes an elevated rate of translation of the gene compared to
the endogenous translation rate for that gene. Methods of testing
for overexpression are well known in the art, for example
transcribed RNA levels can be assessed using rtPCR and protein
levels can be assessed using SDS page gel analysis.
[0112] Recombinant: A recombinant nucleic acid molecule or
polypeptide is one that has a sequence that is not naturally
occurring, has a sequence that is made by an artificial combination
of two otherwise separated segments of sequence, or both. This
artificial combination can be achieved, for example, by chemical
synthesis or by the artificial manipulation of isolated segments of
nucleic acid molecules or polypeptides, such as genetic engineering
techniques. "Recombinant" is also used to describe nucleic acid
molecules that have been artificially manipulated but contain the
same regulatory sequences and coding regions that are found in the
organism from which the nucleic acid was isolated. A recombinant
cell or microorganism is one that contains an exogenous nucleic
acid molecule, such as a recombinant nucleic acid molecule.
[0113] Recombinant cell: A cell that comprises a recombinant
nucleic acid.
[0114] Vector or expression vector: An entity comprising a nucleic
acid molecule that is capable of introducing the nucleic acid, or
being introduced with the nucleic acid, into a cell for expression
of the nucleic acid. A vector can include nucleic acid sequences
that permit it to replicate in the cell, such as an origin of
replication. A vector can also include one or more selectable
marker genes and other genetic elements known in the art. Examples
of suitable vectors are found below.
[0115] Unless explained otherwise, all technical and scientific
terms used herein have the same meaning as commonly understood to
one of ordinary skill in the art to which this disclosure belongs.
Although methods and materials similar or equivalent to those
described herein can be used in the practice or testing of the
present disclosure, suitable methods and materials are described
below.
[0116] Exogenous nucleic acids encoding enzymes involved in a
metabolic pathway for producing polyhydroxyalkanoates can be
introduced stably or transiently into a cell using techniques well
known in the art, including electroporation, calcium phosphate
precipitation, DEAE-dextran mediated transfection,
liposome-mediated transfection, conjugation, transduction, and the
like. For stable transformation, a nucleic acid can further include
a selectable marker. Suitable selectable markers include antibiotic
resistance genes that confer, for example, resistance to neomycin,
tetracycline, chloramphenicol, or kanamycin, genes that complement
auxotrophic deficiencies, and the like. (See below for more
detail.)
[0117] Various embodiments of the invention use an expression
vector that includes a heterologous nucleic acid encoding a protein
involved in a metabolic or biosynthetic pathway. Suitable
expression vectors include, but are not limited to viral vectors,
such as baculovirus vectors or those based on vaccinia virus, polio
virus, adenovirus, adeno-associated virus, SV40, herpes simplex
virus, and the like; phage vectors, such as bacteriophage vectors;
plasmids; phagemids; cosmids; fosmids; bacterial artificial
chromosomes; P1-based artificial chromosomes; yeast plasmids; yeast
artificial chromosomes; and any other vectors specific for cells of
interest.
[0118] Useful vectors can include one or more selectable marker
genes to provide a phenotypic trait for selection of transformed
cells. The selectable marker gene encodes a protein necessary for
the survival or growth of transformed cells grown in a selective
culture medium. Cells not transformed with the vector containing
the selectable marker gene will not survive in the culture medium.
Typical selection genes encode proteins that (a) confer resistance
to antibiotics or other toxins, e.g., ampicillin, neomycin,
methotrexate, or tetracycline, (b) complement auxotrophic
deficiencies, or (c) supply critical nutrients not available from
complex media, e.g., the gene encoding D-alanine racemase for
Bacilli. In alternative embodiments, the selectable marker gene is
one that encodes dihydrofolate reductase or confers neomycin
resistance (for use in eukaryotic cell culture), or one that
confers tetracycline or ampicillin resistance (for use in a
prokaryotic cell, such as E. coli).
[0119] The coding sequence in the expression vector is operably
linked to an appropriate expression control sequence (promoters,
enhancers, and the like) to direct synthesis of the encoded gene
product. Such promoters can be derived from microbial or viral
sources, including CMV and SV40. Depending on the cell/vector
system utilized, any of a number of suitable transcription and
translation control elements, including constitutive and inducible
promoters, transcription enhancer elements, transcription
terminators, etc. can be used in the expression vector (see e.g.,
Bitter et al. (1987) Methods in Enzymology, 153:516-544).
[0120] Suitable promoters for use in prokaryotic cells include but
are not limited to: promoters capable of recognizing the T4, T3,
Sp6, and T7 polymerases; the P.sub.R and P.sub.L promoters of
bacteriophage lambda; the trp, recA, heat shock, and lacZ promoters
of E. coli; the alpha-amylase and the sigma-specific promoters of
B. subtilis; the promoters of the bacteriophages of Bacillus;
Streptomyces promoters; the int promoter of bacteriophage lambda;
the bla promoter of the beta-lactamase gene of pBR322; and the CAT
promoter of the chloramphenicol acetyl transferase gene.
Prokaryotic promoters are reviewed by Glick, J. Ind. Microbiol.
1:277 (1987); Watson et al, Molecular Biology of the Gene, 4th Ed.,
Benjamin Cummins (1987); and Sambrook et al., In: Molecular
Cloning: A Laboratory Manual, 3.sup.rd ed., Cold Spring Harbor
Laboratory Press (2001).
[0121] Non-limiting examples of suitable promoters for use within a
eukaryotic cell are typically viral in origin and include the
promoter of the mouse metallothionein I gene (Hamer et al. (1982)
J. Mol. Appl. Gen. 1:273); the TK promoter of Herpes virus
(McKnight (1982) Cell 31:355); the SV40 early promoter (Benoist et
al. (1981) Nature (London) 290:304); the Rous sarcoma virus
promoter; the cytomegalovirus promoter (Foecking et al. (1980) Gene
45:101); the yeast gal4 gene promoter (Johnston et al. (1982) PNAS
(USA) 79:6971; Silver et al. (1984) PNAS (USA) 81:5951); and the
IgG promoter (Orlandi et al. (1989) PNAS (USA) 86:3833).
[0122] Coding sequences can be operably linked to an inducible
promoter. Inducible promoters are those wherein addition of an
effector induces expression. Suitable effectors include proteins,
metabolites, chemicals, or culture conditions capable of inducing
expression. Suitable inducible promoters include but are not
limited to the lac promoter (regulated by IPTG or analogs thereof),
the lacUV5 promoter (regulated by IPTG or analogs thereof), the tac
promoter (regulated by IPTG or analogs thereof), the trc promoter
(regulated by IPTG or analogs thereof), the araBAD promoter
(regulated by L-arabinose), the phoA promoter (regulated by
phosphate starvation), the recA promoter (regulated by nalidixic
acid), the proU promoter (regulated by osmolarity changes), the
cst-1 promoter (regulated by glucose starvation), the tetA promoter
(regulated by tetracycline), the cadA promoter (regulated by pH),
the nar promoter (regulated by anaerobic conditions), the p.sub.L
promoter (regulated by thermal shift), the cspA promoter (regulated
by thermal shift), the T7 promoter (regulated by thermal shift),
the T7-lac promoter (regulated by IPTG), the T3-lac promoter
(regulated by IPTG), the T5-lac promoter (regulated by IPTG), the
T4 gene 32 promoter (regulated by T4 infection), the nprM-lac
promoter (regulated by IPTG), the VHb promoter (regulated by
oxygen), the metallothionein promoter (regulated by heavy metals),
the MMTV promoter (regulated by steroids such as dexamethasone) and
variants thereof.
[0123] Alternatively, a coding sequence can be operably linked to a
repressible promoter. Repressible promoters are those wherein
addition of an effector represses expression. Examples of
repressible promoters include but are not limited to the trp
promoter (regulated by tryptophan); tetracycline-repressible
promoters, such as those employed in the "TET-OFF"-brand system
(Clontech, Mountain View, Calif.); and variants thereof.
[0124] In some versions, the cell is genetically modified with a
heterologous nucleic acid encoding a biosynthetic pathway gene
product that is operably linked to a constitutive promoter.
Suitable constitutive promoters are known in the art and include
constitutive adenovirus major late promoter, a constitutive MPSV
promoter, and a constitutive CMV promoter.
[0125] The relative strengths of the promoters described herein are
well-known in the art.
[0126] In some versions, the cell is genetically modified with an
exogenous nucleic acid encoding a single protein. In other
embodiments, a modified cell is one that is genetically modified
with exogenous nucleic acids encoding two or more proteins. Where
the cell is genetically modified to express two or more proteins,
those nucleic acids can each be contained in a single or in
separate expression vectors. When the nucleic acids are contained
in a single expression vector, the nucleotide sequences may be
operably linked to a common control element (e.g., a promoter),
that is, the common control element controls expression of all of
the coding sequences in the single expression vector.
[0127] When the cell is genetically modified with heterologous
nucleic acids encoding two or more proteins, one of the nucleic
acids can be operably linked to an inducible promoter, and one or
more of the nucleic acids can be operably linked to a constitutive
promoter. Alternatively, all can be operably linked to inducible
promoters or all can be operably linked to constitutive
promoters.
[0128] Nucleic acids encoding enzymes desired to be expressed in a
cell may be codon-optimized for that particular type of cell. Codon
optimization can be performed for any nucleic acid by
"OPTIMUMGENE"-brand gene design system by GenScript (Piscataway,
N.J.).
[0129] The introduction of a vector into a bacterial cell may be
performed by protoplast transformation (Chang and Cohen (1979)
Molecular General Genetics, 168:111-115), using competent cells
(Young and Spizizen (1961) Journal of Bacteriology, 81:823-829;
Dubnau and Davidoff-Abelson (1971) Journal of Molecular Biology,
56: 209-221), electroporation (Shigekawa and Dower (1988)
Biotechniques, 6:742-751), or conjugation (Koehler and Thorne
(1987) Journal of Bacteriology, 169:5771-5278). Commercially
available vectors for expressing heterologous proteins in bacterial
cells include but are not limited to pZERO, pTrc99A, pUC19, pUC18,
pKK223-3, pEX1, pCAL, pET, pSPUTK, pTrxFus, pFastBac, pThioHis,
pTrcHis, pTrcHis2, and pLEx, in addition to those described in the
following Examples.
[0130] Methods for transforming yeast cells with heterologous DNA
and producing heterologous polypeptides therefrom are disclosed by
Clontech Laboratories, Inc., Palo Alto, Calif., USA (in the product
protocol for the "YEASTMAKER"-brand yeast tranformation system
kit); Reeves et al. (1992) FEMS Microbiology Letters 99:193-198;
Manivasakam and Schiestl (1993) Nucleic Acids Research
21(18):4414-5; and Ganeva et al. (1994) FEMS Microbiology Letters
121:159-64. Expression and transformation vectors for
transformation into many yeast strains are available. For example,
expression vectors have been developed for the following yeasts:
Candida albicans (Kurtz, et al. (1986) Mol. Cell. Biol. 6:142);
Candida maltosa (Kunze et al. (1985) J. Basic Microbiol. 25:141);
Hansenula polymorpha (Gleeson et al. (1986) J. Gen. Microbiol.
132:3459) and Roggenkamp et al. (1986) Mol. Gen. Genet. 202:302);
Kluyveromyces fragilis (Das et al. (1984) J. Bacteriol. 158:1165);
Kluyveromyces lactis (De Louvencourt et al. (1983) J. Bacteriol.
154:737) and Van den Berg et al. (1990) Bio/Technology 8:135);
Pichia quillerimondii (Kunze et al. (1985) J. Basic Microbiol.
25:141); Pichia pastoris (Cregg et al. (1985) Mol. Cell. Biol.
5:3376; U.S. Pat. No. 4,837,148; and U.S. Pat. No. 4,929,555);
Saccharomyces cerevisiae (Hinnen et al. (1978) Proc. Natl. Acad.
Sci. USA 75:1929 and Ito et al. (1983) J. Bacteriol. 153:163);
Schizosaccharomyces pombe (Beach et al. (1981) Nature 300:706); and
Yarrowia lipolytica (Davidow et al. (1985) Curr. Genet. 10:380-471
and Gaillardin et al. (1985) Curr. Genet. 10:49).
[0131] Suitable procedures for transformation of Aspergillus cells
are described in EP 238 023 and U.S. Pat. No. 5,679,543. Suitable
methods for transforming Fusarium species are described by
Malardier et al., Gene, 1989, 78:147-56 and WO 96/00787. Yeast may
be transformed using the procedures described by Becker and
Guarente, In Abelson, J. N. and Simon, M. I., editors, Guide to
Yeast Genetics and Molecular Biology, Methods in Enzymology, Volume
194, pp 182-187, Academic Press, Inc., New York; Ito et al. (1983)
Journal of Bacteriology, 153: 163; and Hinnen et al. (1978) PNAS
USA, 75:1920.
[0132] The elements and method steps described herein can be used
in any combination whether explicitly described or not.
[0133] All combinations of method steps as used herein can be
performed in any order, unless otherwise specified or clearly
implied to the contrary by the context in which the referenced
combination is made.
[0134] As used herein, the singular forms "a," "an," and "the"
include plural referents unless the content clearly dictates
otherwise.
[0135] Numerical ranges as used herein are intended to include
every number and subset of numbers contained within that range,
whether specifically disclosed or not. Further, these numerical
ranges should be construed as providing support for a claim
directed to any number or subset of numbers in that range. For
example, a disclosure of from 1 to 10 should be construed as
supporting a range of from 2 to 8, from 3 to 7, from 5 to 6, from 1
to 9, from 3.6 to 4.6, from 3.5 to 9.9, and so forth.
[0136] All patents, patent publications, and peer-reviewed
publications (i.e., "references") cited herein are expressly
incorporated by reference to the same extent as if each individual
reference were specifically and individually indicated as being
incorporated by reference. In case of conflict between the present
disclosure and the incorporated references, the present disclosure
controls.
[0137] It is understood that the invention is not confined to the
particular construction and arrangement of parts herein illustrated
and described, but embraces such modified forms thereof as come
within the scope of the claims.
EXAMPLES
Summary
[0138] The following Examples present a rational approach for
producing mcl-PHA homopolymer from an unrelated carbon source
(i.e., glucose) in E. coli. A characterization of a panel of mutant
E. coli strains to determine the impact of .beta.-oxidation enzymes
on fatty acid consumption and mcl-PHA synthesis is presented. A
characterization of two PHA synthases (PhaC) and four enoyl-CoA
hydratases (PhaJ) for producing mcl-PHA in E. coli, thereby
identifying a suitable combination for making mcl-PHA, is also
presented. An examination of the impact of different modes of
regulating acyl-CoA synthetases on PHA titer is shown. Finally,
engineering of a strain of E. coli to produce mcl-PHA with a
composition matching the product profile of the expressed
thioesterase is shown. The strategy involves constructing a strain
of E. coli in which key genes in fatty acid .beta.-oxidation are
deleted and BTE, phaJ3 and phaC2 from Pseudomonas aeruginosa PAO1,
and PP.sub.--0763 from P. putida KT2440 are overexpressed. The
resulting strain is shown to produce over 15% cell dry weight (CDW)
mcl-PHA when grown in minimal glucose-based media.
Materials and Methods
Bacterial Strains, Reagents, Media, and Growth Conditions
[0139] All strains used in this study are listed in Table 1. E.
coli DH5.alpha. was used to construct and propagate plasmids. E.
coli K-12 MG1655 .DELTA.araBAD was used as the base strain for
studying .beta.-oxidation and PHA production. Chemicals and
reagents were purchased from Fisher Scientific (Pittsburgh, Pa.)
unless otherwise specified. Enzymes used for cloning were purchased
from New England Biolabs (Ipswich, Mass.). Oligonucleotides were
purchased from Integrated DNA Technologies, Inc. (Coralville, Iowa)
and sequences are listed in Table 2. For all growth experiments,
single colonies were used to inoculate 5 mL starter cultures that
were grown overnight prior to inoculation of experimental cultures.
All growth experiments were performed at 37.degree. C. in a rotary
shaker (250 rpm). Where necessary, cultures were supplemented with
100 .mu.g mL.sup.-1 ampicillin and/or 34 .mu.g mL.sup.-1
chloramphenicol.
TABLE-US-00003 TABLE 1 Strains and plasmids used in this study.
Strain/Plasmid Relevant Genotype/Property Source or Reference
Strains E. coli K-12 F.sup.- .lamda..sup.- ilvG.sup.- rfb-50 rph-1
ECGSC MG1655 E. coli LS5218 F.sup.+ fadR601 atoC512(Const) ECGSC E.
coli DH10B F.sup.- mcrA .DELTA.(mrr-hsdRMS-mcrBC)
.PHI.80lacZ.DELTA.M15 .DELTA.lacX74 Invitrogen recA1 endA1 araD139
.DELTA.(ara, leu)7697 galU galK .lamda..sup.- rpsL nupG E. coli
DH5.alpha. F.sup.- .PHI.80lacZ.DELTA.M15 .DELTA.(lacZYA-argF) U169
recA1 endA1 hsdR17 Invitrogen (r.sub.k-, m.sub.k+) phoA supE44
.lamda..sup.- thi.sup.-1 gyrA96 relA1 E. coli DY330 F.sup.-
.lamda..sup.- rph-1 INV(rrnD, rrnE) .DELTA.lacU169 gal490
pgl.DELTA.8 .lamda.cI857 (Yu et al., 2000) .DELTA.(cro-bioA)
Pseudomonas Source for phaC1-2, phaJ1-4 ATCC BAA-47 .TM. aeruginosa
PAO1 Pseudomonas Source for PP_0763 ATCC 47054 .TM. putida KT2440
NRD204 MG1655 .DELTA.araBAD::cat (De Lay and Cronan, 2007) araBAD
MG1655 .DELTA.araBAD This work A MG1655 .DELTA.araBAD .DELTA.fadA
This work B MG1655 .DELTA.araBAD .DELTA.fadB This work E MG1655
.DELTA.araBAD .DELTA.fadE This work I MG1655 .DELTA.araBAD
.DELTA.fadI This work J MG1655 .DELTA.araBAD .DELTA.fadJ This work
R MG1655 .DELTA.araBAD .DELTA.fadR This work RA MG1655
.DELTA.araBAD .DELTA.fadR .DELTA.fadA This work RB MG1655
.DELTA.araBAD .DELTA.fadR .DELTA.fadB This work RE MG1655
.DELTA.araBAD .DELTA.fadR .DELTA.fadE This work RI MG1655
.DELTA.araBAD .DELTA.fadR .DELTA.fadI This work RJ MG1655
.DELTA.araBAD .DELTA.fadR .DELTA.fadJ This work AI MG1655
.DELTA.araBAD .DELTA.fadA .DELTA.fadI This work BJ MG1655
.DELTA.araBAD .DELTA.fadB .DELTA.fadJ This work AB MG1655
.DELTA.araBAD .DELTA.fadAB This work IJ MG1655 .DELTA.araBAD
.DELTA.fadIJ This work RAI MG1655 .DELTA.araBAD .DELTA.fadR
.DELTA.fadA .DELTA.fadI This work RBJ MG1655 .DELTA.araBAD
.DELTA.fadR .DELTA.fadB .DELTA.fadJ This work RAB MG1655
.DELTA.araBAD .DELTA.fadR .DELTA.fadA .DELTA.fadB This work RIJ
MG1655 .DELTA.araBAD .DELTA.fadR .DELTA.fadIJ This work ABU MG1655
.DELTA.araBAD .DELTA.fadAB .DELTA.fadIJ This work RABIJ MG1655
.DELTA.araBAD .DELTA.fadR .DELTA.fadAB .DELTA.fadIJ This work
.PHI.(P.sub.trc-fadD) MG1655 .DELTA.araBAD .PHI.(P.sub.trc-fadD)
This work SA01 MG1655 .DELTA.araBAD .DELTA.fadR .DELTA.fadIJ
fadBA::.PHI.(P.sub.trc-BTE) This work Plasmids pCP20 FLP.sup.+,
.lamda. cI857.sup.+, .lamda. p.sub.R Rep.sup.ts, Ap.sup.R, Cm.sup.R
(Cherepanov and Wackernagel, 1995) pKD13 Template plasmid for gene
disruption. Kan.sup.R cassette flanked (Datsenko and by FRT sites.
Amp.sup.R Wanner, 2000) pTrc99A P.sub.trc promoter, pBR322 origin,
Amp.sup.R (Amann et al., 1988) pTrc99A-fadD fadD cloned as a Kpn I
-Xba I fragment into pTrc99a This work pTrc99A-BTE pTrc99A carrying
BTE under Ptrc control, Amp.sup.R (Hoover et al., 2011) pMSB6
pTrc99A with altered MCS This work pMSB6-J1 pMSB6 containing phaJ1
gene (P. aeruginosa) This work pMSB6-J2 pMSB6 containing phaJ2 gene
(P. aeruginosa) This work pMSB6-J3 pMSB6 containing phaJ3 gene (P.
aeruginosa) This work pMSB6-J4 pMSB6 containing phaJ4 gene (P.
aeruginosa) This work pBAD33 P.sub.BAD promoter, pACYC origin,
Cm.sup.R (Guzman et al., 1995) pBAD33-C280* pBAD33 araE C280*
.DELTA.281-292 (Lee et al., 2007) pBAD33*-C1 pBAD33-C280*
containing phaC1 gene (P. aeruginosa) This work pBAD33*-C2
pBAD33-C280* containing phaC2 gene (P. aeruginosa) This work pDA-JC
pMSB6 containing phaJ3 and phaC2 genes (P. aeruginosa) This work
pDA-JAC pDA-JC with PP_0763 cloned between phaJ3 and phaC2 This
work pBTE-int pTrc99A containing BTE with cat-FRT cassette from
pKD3 (Youngquist et al., 2012) (Datsenko and Wanner, 2000) inserted
5' of lacI.sup.Q
TABLE-US-00004 TABLE 2 Oligonucleotides used in this study. Primer
Restriction Name Sequence Enzyme phaJ1-F
GACGATGAATTCAGGAGGTATTAATAATGAGCCAGGTC EcoRI CAGAACATTC (SEQ ID NO:
25) phaJ1-R GACGATGGATCCGGCCCGACGGTAGGGAAA BamHI (SEQ ID NO: 26)
phaJ2-F GACGATGAATTCAGGAGGTATTAATAATGGCGCTCGAT EcoRI CCTGAGGTGC
(SEQ ID NO: 27) phaJ2-R GACGATGGATCCCTTCGCTTCAGTCCGGCCGCT BamHI
(SEQ ID NO: 28) phaJ3-F GACGATGAATTCAGGAGGTATTAATAATGCCCACCGCC
EcoRI TGGCTCGAC (SEQ ID NO: 29) phaJ3-R
GACGAAGGATCCTCAGCCCTGTAGCCGGCTCCA BamHI (SEQ ID NO: 30) phaJ4-F
GACGATGAATTCAGGAGGTATTAATAATGCCATTCGTA EcoRI CCCGTAGCAG (SEQ ID NO:
31) phaJ4-R GACGATGGATCCTCAGACGAAGCAGAGGCTGAG BamHI (SEQ ID NO: 32)
phaC1-F GGGGAGCTCAGGAGGTATAATTAATGAGTCAGAAGAAC SacI AATAACGAG (SEQ
ID NO: 33) phaC1-R GGGGGTACCTCATCGTTCATGCACGTAGGT KpnI (SEQ ID NO:
34) phaC2-F GGGGAGCTCAGGAGGTATAATTAATGCGAGAAAAGCA SacI GGAATCGGG
(SEQ ID NO: 35) phaC2-R GGGGGTACCTCAGCGTATATGCACGTAGGTGC KpnI (SEQ
ID NO: 36) phaC2-F2 GGGTCTAGAAGGAGGTATAATTAATGCGAGAAAAGCA XbaI
GGAATCGGG (SEQ ID NO: 37) phaC2-R2 GGGAAGCTTTCAGCGTATATGCACGTAGGTGC
HindIII (SEQ ID NO: 38) acs-F
GGGGGTACCAGGAGGTATAATTAATGTTGCAGACACGC KpnI ATCATC (SEQ ID NO: 39)
acs-R GGGTCTAGATTACAACGTGGAAAGGAACGC XbaI (SEQ ID NO: 40) IJ::BTE-F
GGTCAGACCACTTTATTTATTTTTTTACAGGGGAGTGTT n/a AGCGGCATGCGTTCCTATTCC
(SEQ ID NO: 41) IJ::BTE-R CTCCGCCATTCAGCGCGGATTCATATAGCTTTGACCTTC
n/a TTAAACACGAGGTTCCGCCGG (SEQ ID NO: 42) R::BTE-F
GAGTCCAACTTTGTTTTGCTGTGTTATGGAAATCTCACT n/a AGCGGCATGCGTTCCTATTCC
(SEQ ID NO: 43) R::BTE-R ACCCCTCGTTTGAGGGGTTTGCTCTTTAAACGGAAGGG n/a
ATTAAACACGAGGTTCCGCCGG (SEQ ID NO: 44) C280*-F
GGGCTCGAGTTAACCGGCACGGAACTCGCTCG XhoI (SEQ ID NO: 45) C280*-R
GGGCTCGAGTTGGTAACGAATCAGACAATTGACGGC XhoI (SEQ ID NO: 46)
PfadD-kan-F TGAATAATTGCTTGTTTTTAAAGAAAAAGAAACAGCGG n/a
CTGGTCCGCTGTGTGTAGGCTGGAGCTGCTTC (SEQ ID NO: 47) PfadD-kan-R
TCGATGGTGTCAACGTAAATGATTCCGGGGATCCGTCG n/a ACC (SEQ ID NO: 48)
PfadD-Trc-F CATTTACGTTGACACCATCGA (SEQ ID NO: 49) n/a PfadD-sew-R
TCAGGCTTTATTGTCCACTTTG (SEQ ID NO: 50) n/a fadIJ::Cm-F
CAGGTCAGACCACTTTATTTATTTTTTTACAGGGGAGTG n/a
TGAAGCGGCATGCGTTCCTATTCC (SEQ ID NO: 51) fadIJ::Cm-R
TTGCAGGTCAGTTGCAGTTGTTTTCCAAAAACTTTCCCC n/a AGTGTAGGCTGGAGCTGCTTC
(SEQ ID NO: 52) fadR::Cm-F TCTGGTACGACCAGATCACCTTGCGGATTCAGGAGACT
n/a GAGAAGCGGCATGCGTTCCTATTCC (SEQ ID NO: 53) fadR::Cm-R
AACCCGCTCAAACACCGTCGCAATACCCTGACCCAGAC n/a CGGTGTAGGCTGGAGCTGCTTC
(SEQ ID NO: 54)
[0140] For dodecanoic acid catabolism experiments (FIGS. 2A and 3),
each strain was cultured in 25 mL of LB to an optical density at
600 nm (OD.sub.600) of 1.0. Cultures were centrifuged
(1,000.times.g for 20 min) and resuspended in 50 mL of M9 minimal
media supplemented with 0.25 g L.sup.-1 sodium dodecanoate from a 5
g L.sup.-1 sodium dodecanoate aqueous stock solution. This amount
was chosen because higher levels impaired growth of E. coli MG1655
.DELTA.araBAD (data not shown). Under these conditions, soluble
dodecanoic acid existed in equilibrium with a solid precipitate.
After transfer, cultures were incubated at 37.degree. C. with
shaking and 2.5 mL culture samples were taken at 24 and 48 h for
FAME analysis. In the case of fadD overexpression constructs, 1 mM
isopropyl f3-D-thiogalactopyranoside (IPTG) was added at an
OD.sub.600 of 0.02 and again after resuspension in minimal
media.
[0141] For dodecanoic acid production experiments (FIG. 2B), each
strain was inoculated to OD.sub.600 of 0.05 in 5 mL of LB+0.4%
(D)-glucose and induced with 1 mM IPTG at an OD.sub.600 of 0.2.
After induction, cultures were incubated for 48 h at 37.degree. C.
with shaking at which point, cultures were harvested for PHA and
FAME analysis.
[0142] For shake flask experiments summarized by Table 3, 35 mL of
LB was inoculated to OD.sub.600 0.05 and incubated with shaking
until cultures reached OD.sub.600 1.0. Cultures were centrifuged
(1,000.times.g for 20 min) and the cell pellet resuspended in 50 mL
M9 minimal media supplemented with 2.5 g L.sup.-1 dodecanoic acid
and inducer(s) (1 mM IPTG; 0.2% (L)-arabinose). Cultures were
harvested at 96 h for PHA and FAME analysis.
[0143] For PHA production experiments detailed in Table 4 and FIG.
4, 50 mL of MOPS+1% (D)-glucose was inoculated to OD.sub.600 of
0.05 and induced with 1 mM IPTG at an OD.sub.600 of 0.2. After
induction, cultures were incubated for 96 h at 37.degree. C. with
shaking at which point, cultures were harvested for PHA and FAME
analysis. For strains lacking chromosomal expression of BTE, 0.25 g
L.sup.-1 sodium dodecanoate from a 5 g L.sup.-1 sodium dodecanoate
aqueous stock solution was added at the time of induction.
[0144] Bioreactor experiments were performed in a 3 L stirred
bioreactor (Applikon Biotechnology, Inc., Schiedam, Netherlands)
using a 1.0 L working volume. Temperature was maintained at
37.degree. C. using an electric heat blanket and temperature, pH,
and dissolved oxygen (DO.sub.2) were monitored using specific
probes. Vessel pH was maintained at 7.00.+-.0.05 by addition of 1M
NaOH or 1M HCl solutions. Agitation was provided by a single
impeller with the stirrer speed set to 700 rpm. Stirrer speed was
occasionally increased to ensure the DO.sub.2 content did not
decrease below 40% saturation in order to maintain an aerobic
environment (Becker et al., 1997; Tseng et al., 1996). Air inflow
was maintained at 1.5 L min.sup.-1.
[0145] Bioreactor experiments were inoculated at an OD.sub.600 of
0.05 with a culture of strain SA01 harboring plasmid pDA-JAC grown
to an OD.sub.600 of .gtoreq.2.5 in MOPS minimal media supplemented
with 1% glucose. Induction with 1 mM IPTG occurred when the
OD.sub.600 of the bioreactor reached 0.2. The reactor was operated
in batch mode with one addition of 10 g of glucose (50 mL of a 20%
(w/v) glucose solution) at 24 h post-induction. The OD.sub.600 of
the culture was monitored periodically and 15 mL of culture taken
every 24 h for FAME and PHA analysis. The contents of the
bioreactor were harvested at 96 h post-induction for PHA and FAME
analysis.
Plasmid Construction
[0146] All plasmids used in this study are listed in Table 1.
Plasmid pBAD33-C280* (Lee et al., 2007) was constructed by PCR
amplification of plasmid pBAD33 with primers C280*-F/R (Table 2)
(Guzman et al., 1995). The PCR product was treated with Dpn I and
Xho I digestion and circularized by ligation with T4 DNA ligase.
Genomic DNA was isolated from P. putida KT2440 and P. aeruginosa
PAO1 with a Wizard.RTM. Genomic DNA Purification Kit (Promega). PHA
genes phaJ1-4 and phaC1-2 were amplified by PCR from a P.
aeruginosa PAO1 genomic DNA template with the respective phaC and
phaJ primers (Table 2). PP.sub.--0763 was amplified by PCR from a
P. putida KT2440 genomic DNA template with primers acs-F/R (Table
2). All constructs were confirmed by DNA sequence analysis.
Annotated sequence files for relevant constructs were deposited in
GenBank.
Chromosome Engineering
[0147] Chromosomal gene deletions were created in E. coli K12
MG1655 .DELTA.araBAD by P1 transduction (Thomason et al., 2007)
using phage lysates generated from members of the KEIO collection
(Baba et al., 2006). Deletions of fadBA and fadIJ were generated as
described previously using pKD13 as template (Datsenko and Wanner,
2000). Chromosomal integration of a .PHI.(P.sub.trc-BTE) expression
cassette (a fusion of the IPTG inducible trc promoter with BTE) was
constructed as described previously (Youngquist et al., 2012).
Briefly, an insertion template was generated by PCR amplification
of a fragment comprising lacI.sup.Q-P.sub.trc-BTE-FRT-Cm.sup.R-FRT
from plasmid pBTE-int. Primers contained 40 base pairs of sequence
homology to regions of the E. coli chromosome flanking the fadBA
locus (Table 2) to guide .lamda. red mediated recombination. To
construct the fadD promoter replacement, .PHI.(P.sub.trc-fadD), the
region consisting of lacI.sup.Q-P.sub.trc-fadD was PCR amplified
off of plasmid pTrc-fadD. A region of pKD13 comprising the
kanamycin resistance cassette flanked by FRT sites was PCR
amplified separately. The two PCR products were stitched together
in a third PCR, generating a linear DNA that was integrated onto
the chromosome of E. coli DY330 via .lamda. red mediated
recombination. For each mutant strain, resistance markers were
removed by inducing FLP recombinase encoded on plasmid pCP20 which
was subsequently cured by growth at a non-permissive temperature
(Datsenko and Wanner, 2000). All chromosomal mutations were
verified by colony PCR.
Fatty Acid and PHA Extraction and Characterization
[0148] FAME analysis was performed on 2.5 mL of culture or
supernatant as described previously (Lennen et al., 2010). For PHA
analysis, cells were harvested by centrifugation (3000.times.g for
25 min), washed with 25 mL 1.times. phosphate buffered saline
(PBS), and lyophilized overnight. PHA content was analyzed by GC/MS
based on the method of Kato et al. (Kato et al., 1996). PHA was
converted to the corresponding monomer-esters by combining 2 mL of
chloroform and 2 mL of 3% H.sub.2SO.sub.4 in methanol (v/v) with 10
mg of lyophilized cells in a 10 mL disposable glass centrifuge
tube. 50 .mu.L of 10 mg mL.sup.-1 pentadecanoic acid in ethanol was
added as an internal standard. The mixture was heated at
105.degree. C. in a heat block for 24 hours followed by addition of
5 mL of 100 mg mL.sup.-1 NaHCO.sub.3 in water. The mixture was
vortexed and centrifuged (1,000.times.g for 10 min) and the aqueous
layer was removed by aspiration. The organic (chloroform) phase (1
.mu.L) was analyzed using a Shimadzu GCMS QP2010S gas chromatograph
mass spectrometer equipped with an AOC-20i auto-injector and a
Restek Rxi.RTM.-5 ms column (catalog #13423). The temperature
program used was as follows: 60.degree. C. hold for 1 minute, ramp
from 60.degree. C. to 230.degree. C. at 10.degree. C. per minute
and a final hold at 230.degree. C. for 10 minutes. The MS was
operated in scanning mode between 35 and 500 m/z.
PHA Purification and Nuclear Magnetic-Resonance Spectroscopy
[0149] PHA was extracted for analysis by nuclear magnetic-resonance
(NMR) as described previously (Jiang et al., 2006) and modified
based on communications with Chris Nomura (State University of New
York). Briefly, lyophilized cells were washed with methanol to
remove fatty acids and other impurities followed by a second
lyophilization step. The material was extracted with 120 mL
refluxing chloroform in a Soxhlet apparatus followed by evaporation
of the chloroform to recover the purified PHA. 10-15 mg of product
was dissolved in 1 mL deuterated chloroform and analyzed at room
temperature on a Bruker AC-300 spectrometer for .sup.1H NMR and on
a Varian Mercury-300 spectrometer for .sup.13C NMR.
Results
Effect of Fad Deletions on Dodecanoic Acid Catabolism
[0150] .beta.-oxidation of fatty acids occurs in three stages.
First, FFA are imported across the outer membrane via FadL and
activated as CoA thioesters by FadD in the inner membrane. The
acyl-CoA thioesters are a key regulatory signal which abrogates the
DNA binding ability of FadR. In the absence of acyl-CoAs, FadR
represses expression of enzymes involved in .beta.-oxidation. Once
activated, acyl-CoAs are catabolized to acetyl-CoA via an iterative
pathway comprised of four enzymatic reactions (FIG. 1)--acyl-CoA
dehydrogenation (FadE), enoyl-CoA hydration (FadB),
(3S)-hydroxyacyl-CoA dehydrogenation (FadB), and ketoacyl-CoA
thiolation (FadA). Three additional fad genes--fadK, fadI and fadJ
have strong sequence homology to fadD, fadA and fadB, respectively
and have been shown to be critical for anaerobic beta-oxidation
(Campbell et al., 2003). Each cycle ends when FadA (or FadI)
cleaves a ketoacyl-CoA to generate an acetyl-CoA and an acyl-CoA
reduced in length by two carbons that is the substrate for the next
round. Finally, E. coli possesses additional .beta.-oxidation
capacity in the ato genes which are responsible for processing
short-chain FFAs.
[0151] The metabolic engineering strategy for producing mcl-PHA
from endogenously synthesized fatty acids described herein involves
the disruption of .beta.-oxidation such that (R)-3-hydroxyacyl-CoA
thioesters can be polymerized but not catabolized to acetyl-CoA.
The ability of strains harboring various deletions in
.beta.-oxidation (fad) genes to catabolize dodecanoic acid after 24
and 48 h of shake flask cultivation (FIG. 2A) was therefore tested.
The base strain, K12 MG1655 .DELTA.araBAD, was observed not to
completely catabolize all of the dodecanoic acid until 48 h, while
a fadR mutant was able to consume all of the dodecanoic acid within
24 h. A fadB deletion, which based on previous reports was expected
to greatly impair dodecanoic acid catabolism under aerobic
conditions, consumed .about.20% of the dodecanoic acid. A
.DELTA.fadB, .DELTA.fadJ double knockout strain completely blocked
dodecanoic acid consumption over the course of 48 h. Similarly, a
.DELTA.fadA strain consumed .about.20% of the dodecanoic acid,
while a .DELTA.fadA, .DELTA.fadI double mutant demonstrated
negligible dodecanoic acid consumption. The performance of other
fad strains and the effect of a fadR deletion combined with these
strains, which generally improved the rate of dodecanoic acid
metabolism, are shown in FIG. 2A.
[0152] To determine if metabolism of exogenously fed dodecanoic
acid correlated with metabolism of endogenously produced FFAs,
.beta.-oxidation deletion strains were transformed with pTrc99a-BTE
and grown for 48 h on LB supplemented with glucose (FIG. 2B). Final
fatty acid concentrations and especially saturated dodecanoic acid
concentrations correlated with exogenous consumption data (FIG.
2A). Specifically, strains capable of complete consumption of
exogenous dodecanoic acid after 48 h accumulated little to no
endogenous dodecanoic acid while strains that were the most
impaired in exogenous C.sub.12 consumption yielded the largest
concentrations of endogenous C.sub.12 FFA. While FFA uptake has
been well studied (DiRusso and Black, 2004), the mechanism of FFA
secretion is poorly understood. It should be noted that the data
presented in FIG. 2B does not distinguish rates of FFA secretion
and reuptake from catabolism of intracellular FFA.
Effect of fadD Regulation on Dodecanoic Acid Catabolism
[0153] The proposed mcl-PHA pathway involves the activation of FFA
and oxidation by FadE to yield enoyl-CoA thioesters. These genes
could be upregulated by increasing the rate of acyl-CoA synthesis
(e.g. replacing P.sub.fadD with a stronger promoter), removing
repression via FadR, or both. Therefore, a fadD overexpression
strain was constructed by replacing the native fadD promoter with
the strong, IPTG inducible trc promoter (Brosius et al., 1985).
Dodecanoic acid consumption in this strain was compared with the
base strain, .DELTA.fadR, and .PHI.(P.sub.trc-fadD) .DELTA.fadR
combination strains (FIG. 3). Interestingly, the .DELTA.fadR strain
completely consumed the dodecanoic acid after 8 h while complete
consumption was not observed for the .PHI.(P.sub.trc-fadD)
overexpression strain until 24 h. Surprisingly, a
.PHI.(P.sub.trc-fadD) .DELTA.fadR combination strain consumed
dodecanoic acid at a rate in between the .PHI.(P.sub.trc-fadD)
overexpression and .DELTA.fadR strains. Deletion of fadR may
provide the additional benefit of upregulating fadE expression,
which is involved in the production of enoyl-CoA thioesters in the
preferred mcl-PHA strategy described herein.
Production of mcl-PHA in fad Strains in the Presence of Exogenous
Dodecanoic Acid
[0154] Two PHA biosynthetic enzymes confer E. coli with the ability
to synthesize mcl-PHA from enoyl-CoA thioesters, a PHA polymerase
(PhaC) and an (R)-specific enoyl-CoA hydratase (PhaJ). P.
aeruginosa DSM1707 phaJ1-4 have been previously characterized in E.
coli LS5218 (Tsuge et al., 2003). Here, genes from P. aeruginosa
PAO1 were selected based on sequence identity with DSM1707 and the
ability of this strain to accumulate mcl-PHA. Individual phaJ and
phaC clones were co-expressed from plasmids pMSB-6 and pBAD33-C280*
respectively in LS5218 grown in the presence of exogenous
dodecanoic acid as a sole carbon source. All phaJ-phaC combinations
yielded mcl-PHA identified as methyl esters of 3-hydroxyacyl-chains
after processing (Table 3). The observed acyl-chains ranged in
length from C.sub.6 to C.sub.14 corresponding to mcl-PHA monomers
(C.sub.6-C.sub.12) and components of lipid A (C.sub.14). The
combination of phaJ3 and phaC2 was selected based on the ability to
produce mcl-PHA containing C.sub.12 monomer units at yields greater
than other combinations tested (Table 3).
[0155] P. aeruginosa phaC2 was cloned downstream of phaJ3 into
pMSB-6 yielding pDA-JC and the plasmid was transformed into a
selection of fad deletions strains for mcl-PHA production. Table 4
shows the ability of a .DELTA.fadR, .DELTA.fadRB, .DELTA.fadRBJ and
.DELTA.fadRABIJ strains to accumulate mcl-PHA as well as the
monomer composition of the resulting polymer. Most notably,
.DELTA.fadR and .DELTA.fadRB strains both produced mcl-PHA with a
heterogeneous monomer composition, although the fraction of
C.sub.12 monomers in the .DELTA.fadRB strain was greatly increased
over that of the .DELTA.fadR strain. The .DELTA.fadRBJ and
.DELTA.fadRABIJ strains were both capable of producing mcl-PHA
homopolymer consisting entirely of C.sub.12 monomers with the yield
of PHA in the .DELTA.fadRABIJ strain slightly improved over that of
the .DELTA.fadRBJ strain. This result was consistent with the
relative rates of endogenous FFA production (FIG. 2B).
TABLE-US-00005 TABLE 3 GC/MS analysis of the composition of mcl-PHA
produced in E. coli LS5218 expressing combinations of two phaC and
four phaJ from P. aeruginosa PAO1 after culturing in the presence
of exogenous dodecanoic acid. Cell Dry PHA Weight content PHA
composition (wt. %) Genotype (g L.sup.-1) (wt. %) C.sub.6 C.sub.8
C.sub.10 C.sub.12 phaC1 phaJ1 1.0 0.3 8.4 90.7 0.0 0.9 phaC1 phaJ2
1.2 4.4 4.8 49.6 28.9 16.8 phaC1 phaJ3 1.4 10.8 3.9 43.5 33.0 19.6
phaC1 phaJ4 1.0 2.8 5.2 52.3 25.6 16.9 phaC1 1.1 0.6 4.7 65.1 22.0
8.3 phaC2 phaJ1 1.0 2.2 34.0 54.8 6.7 4.5 phaC2 phaJ2 1.1 13.9 11.1
35.9 28.8 24.2 phaC2 phaJ3 1.1 19.1 8.2 32.3 32.2 27.3 phaC2 phaJ4
0.9 9.4 9.6 35.0 29.3 26.1 phaC2 1.1 1.8 6.9 48.5 26.7 17.9 Note:
C.sub.6: 3-hydroxyhexanoate; C.sub.8: 3-hydroxyoctanoate; C.sub.10:
3-hydroxydecanoate; C.sub.12: 3-hydroxydodecanoate.
TABLE-US-00006 TABLE 4 GC/MS analysis of the composition of mcl-PHA
produced in a series of E. coli .beta.-oxidation deletion strains
containing plasmid pDA-JC after culturing in the presence of
exogenous dodecanoic acid. Cell Dry PHA Relevant Weight content PHA
composition (wt. %) genotype (g L.sup.-1) (wt. %) C.sub.6 C.sub.8
C.sub.10 C.sub.12 .DELTA.fadR 0.97 .+-. .09 1.71 .+-. .18 4.0 30.3
34.0 31.8 .DELTA.fadRB 0.96 .+-. .08 0.39 .+-. .13 n.d. 8.3 42.4
49.3 .DELTA.fadRBJ 1.10 .+-. .19 0.38 .+-. .15 n.d. n.d. n.d. 100.0
.DELTA.fadRABIJ 0.93 .+-. .02 0.75 .+-. .03 n.d. n.d. n.d. 100.0
Note: C.sub.6: 3-hydroxyhexanoate; C.sub.8: 3-hydroxyoctanoate;
C.sub.10: 3-hydroxydecanoate; C.sub.12: 3-hydroxydodecanoate.
Accumulation of mcl-PHA in a .DELTA.fadRABIJ Strain with Endogenous
Dodecanoic Acid Production
[0156] Expression of the California Bay Laurel (Umbellularia
californica) thioesterase (BTE) in E. coli results in the
accumulation of FFAs composed predominantly (.gtoreq.80%) of
saturated C.sub.12 and unsaturated C.sub.12:1 species with the
remainder comprised mainly of C.sub.14 and unsaturated C.sub.14:1
FFAs (Voelker and Davies, 1994). A codon optimized version of BTE
(Lennen et al., 2010) was integrated into the chromosome of E. coli
K-12 MG1655 .DELTA.araBAD .DELTA.fadR .DELTA.fadIJ into the fadBA
locus, resulting in a .DELTA.fadRABIJ strain with one copy of the
.PHI.(P.sub.trc-BTE) cassette. This strain (SA01) when transformed
with pDA-JC and grown in MOPS minimal media supplemented with 1%
glucose accumulated mcl-PHA at a % CDW on par with a
.DELTA.fadRABIJ strain cultured with exogenous dodecanoic acid
(FIG. 4). A significant amount of residual dodecanoic and
tetradecanoic acid was also observed indicating that there is room
for further pathway optimization.
Effect of Overexpression of PP.sub.--0763 on mcl-PHA Accumulation
in a .DELTA.fadRABIJ Strain with Endogenous Dodecanoic Acid
Production
[0157] Given the presence of excess FFA, it was hypothesized that
the rate of fatty acyl-CoA production was not balanced with FFA
synthesis. Therefore, the predicted acyl-CoA synthetase,
PP.sub.--0763 from P. putida KT2440 was cloned between phaJ3 and
phaC2 in pDA-JC resulting in pDA-JAC. Strain SA01 was transformed
with pDA-JAC which resulted in the production of 9.8% CDW mcl-PHA,
a 5-fold increase compared to the same strain without PP.sub.--0763
(FIG. 4, Table 5). When cultured in a 1 L bioreactor, mcl-PHA
accumulation increased to 17.3% CDW after 96 h. The identity of the
purified product was confirmed to be predominantly
polyhydroxydodecanoate by .sup.1H and .sup.13C NMR (FIGS. 5A and
5B).
TABLE-US-00007 TABLE 5 Results from PHA Production Studies Shown in
FIG. 4 Cell Dry PHA PHA Weight content content PHA composition (wt.
%) Genotype (g L.sup.-1) (g L.sup.-1) (% CDW) C.sub.6 C.sub.8
C.sub.10 C.sub.12 C.sub.14 .DELTA.fadRABIJ 0.9 .+-. .02 0.02 1.7
n.d. n.d. n.d. 43.3 56.7 SA01 1.2 .+-. .07 0.02 1.9 n.d. n.d. n.d.
34.9 65.1 SA01-acs 0.9 .+-. .04 0.09 9.8 n.d. n.d. n.d. 77.0 23.0
Bioreactor 1.3 0.23 17.3 n.d. n.d. n.d. 77.9 22.0 Note: All Strains
harbored plasmids expressing phaJ3 and phaC2. .DELTA.fadRABIJ
strain was fed exogenous dodecanoic acid. PHA values could include
hydroxy-acids extracted from lipid A. Abbreviations: C.sub.6,
3-hydroxyhexanoate; C.sub.8, 3-hydroxyoctanoate; C.sub.10,
3-hydroxydecanoate; C.sub.12, 3-hydroxydodecanoate; C.sub.14,
3-hydroxytetradecanoate.
Cloning and Expression of Phasin Genes
[0158] Phasin genes annotated as "Polyhydroxyalkanoate
granule-associated proteins" on the UniProKB database
(http://www.uniprot.org/) and having locus tags PP.sub.--5008 and
PP.sub.--5007 were cloned from Pseudomonas putida KT2440. The
PP.sub.--5008 gene is homologous to phal, and PP.sub.--5007 is
homologous to phaF. Each phasin gene was expressed in the SA01 E.
coli strain with and without the pDA-JAC vector and cultured in
MOPS+1% glucose in the absence of supplemented fatty acids. As
shown in FIG. 6, expression of the phasin genes drastically
increased C12 and C14 polyhydroxyalkanoate production. Expression
of PP.sub.--5008 in particular resulted in an unexpectedly large
increase in C12 and C14 polyhydroxyalkanoate production.
Discussion
Effect of fad Deletions on Dodecanoic Acid Metabolism
[0159] Previous work has demonstrated that the ability to use fatty
acids .gtoreq.C.sub.12 as a sole carbon source is lost in the case
of deletions in fadB (Dirusso, 1990), however, a fadB(A) phaC.sup.+
strain was still capable of aerobic production of mcl-PHA
heteropolymer, indicating that E. coli can complement fadB activity
(Langenbach et al., 1997; Prieto et al., 1999; Qi et al., 1997; Ren
et al., 2000; Snell et al., 2002). Furthermore, a fadA insertion
mutant was capable of aerobic growth on oleic acid (C.sub.18:1) as
a sole carbon source after extended incubation (<5 days) on
solid media (Campbell et al., 2003), further indicating that
additional .beta.-oxidation activity is present. The data indicate
both E. coli .DELTA.fadA and .DELTA.fadB mutants are capable of
dodecanoic acid metabolism after 24 h, although with reduced
capability compared to WT. Conversely, E. coli .DELTA.fadR
.DELTA.fadA catabolized dodecanoic acid more efficiently than WT
with nearly complete consumption of the dodecanoic acid after 48 h.
As fadR is a negative regulator for fadIf, it is likely that fadIJ
is capable of complementing fadBA and restoring .beta.-oxidation
activity to that of WT. However, a .DELTA.fadR .DELTA.fadB strain
did not show increased dodecanoic acid catabolism over the 48 h
period. Therefore, fadJ may not be able to complement a fadB
deletion as effectively as in the case of fadI with fadA.
[0160] Deletions of fadI or fadD had a minor negative effect on
dodecanoic acid metabolism compared to WT which is expected if
fadBA function as the major contributor to aerobic
.beta.-oxidation. Similarly, .DELTA.fadR .DELTA.fadI and
.DELTA.fadR .DELTA.fadJ strains were comparable to a .DELTA.fadR
strain. An unexpected result was the reduced rate of dodecanoic
acid consumption in both a .DELTA.fadBA and .DELTA.fadIJ double
knockout compared to WT. These data indicate that functional
expression of fadBA is not essential for dodecanoic acid metabolism
under the conditions tested. It is important to note that
dodecanoic acid metabolism was still active in a .DELTA.fadIJ
strain which is in line with previous work that demonstrated both
aerobic and anaerobic growth for a .DELTA.fadIJ (yfcYX) strain on
oleic acid (Campbell et al., 2003).
[0161] Based on the behavior of the aforementioned deletions, it
was anticipated that a .DELTA.fadA .DELTA.fadI or .DELTA.fadB
.DELTA.fadJ strain would be incapable of C12 metabolism. This
result was confirmed for these strains, a .DELTA.fadBA .DELTA.fadIJ
strain and for each of the strains when combined with a fadR
deletion.
Comparison of fadD Overexpression and fadR Deletion on Dodecanoic
Acid Metabolism
[0162] Due to the ability of a fadR deletion to improve the initial
rate of C.sub.12 metabolism, it was hypothesized that
overexpression of fadD would result in a similar phenotype. A
chromosomal trc promoter fusion with fadD, .PHI.(P.sub.trc-fadD),
individually and in combination with a .DELTA.fadR strain, was
therefore tested. Over a 24 h period, it was noted that
.PHI.(P.sub.trc-fadD) was capable of improved C.sub.12 consumption
compared with WT but was not as efficient as a .DELTA.fadR or
.PHI.(P.sub.trc-fadD) .DELTA.fadR combination strain.
Overexpression of fadD increases the cytoplasmic acyl-CoA pool
faster than in WT resulting in faster de-repression of all
.beta.-oxidation genes regulated by fadR, while in a .DELTA.fadR
strain, there is no repression of .beta.-oxidation genes allowing
for faster initial turnover of exogenous fatty acids.
Effect of Soluble vs. Membrane Associated CoA-Synthetases
[0163] Although mcl-PHA production in strain SA01 expressing pDA-JC
was achieved with a defined composition from a non-fatty acid
feedstock, a large amount of endogenously produced FFA remained in
the culture broth. Therefore, it was hypothesized that the limiting
step in PHA biosynthesis was CoA ligation. Or put another way, it
was hypothesized that intracellular FFAs were leaving the cell at a
faster rate than FadD ligation with CoA, the product of which
(acyl-CoA) is not exportable. Two models of the CoA synthetase
reaction can be envisioned (DiRusso and Black, 2004). First,
cytoplasmic FFA, freshly produced by BTE, could be directly bound
by a cytosolic FadD and converted to CoA thioesters. Alternatively,
cytoplasmic FFA could begin to traverse the inner cell membrane,
periplasm, and outer membrane and be re-imported for FadD
activation. The import of extracellular fatty acids across the
outer membrane is facilitated by FadL. Once across the outer
membrane, FFA traverse the periplasm and intercalate into the inner
membrane. FFA then bind to the FadD active site and become
phosphorylated from an ATP donor. The final CoA ligation,
disassociation of FadD from the inner membrane and association of
the fatty acyl-CoA with the cytoplasm likely takes place in one
concerted event. If the rate of re-import is inferior to continued
export (which would be down the concentration gradient) dodecanoic
acid could accumulate extracellularly as was observed in the BTE
expressing strains. The predicted soluble CoA-synthetase encoded by
P. putida gene PP.sub.--0763 (acs), a medium-chain-length acyl-CoA
synthetase, was therefore co-expressed. Co-expressing acs with PHA
biosynthesis genes in SA01 resulted in a 5-fold increase in mcl-PHA
accumulation in shake flasks and a 7.5-fold increase in
3-OH--C.sub.12 content. This data supports the conclusion that
balancing FFA production and CoA activation will be critical to
maximizing mcl-PHA yields.
Bioreactor Scale-Up of mcl-PHA Production from Glucose
[0164] The PHA production strategy described herein is the first to
produce a defined mcl-PHA from an unrelated carbon source. The
highest mcl-PHA production (17.3% CDW) was achieved by cultivating
strain SA01 pDA-JAC in a 1 L bioreactor using a fed-batch strategy.
For comparison, prior studies achieved .about.6% CDW of an
undefined mcl-PHA in E. coli when grown on gluconate (Rehm and
Steinbuchel, 2001) and 11.6% CDW of undefined heteropolymer in E.
coli grown on glucose (Wang et al., 2012). Finally, recent work in
both P. putida and E. coli demonstrated production of mcl-PHA
homopolymer in the case of feeding exogenous fatty acids (Liu et
al., 2011; Tappel et al., 2012). In putida, an 85% C.sub.12-co-15%
C.sub.10 PHA was produced at 9% CDW, and in E. coli, a C.sub.12
homopolymer was produced at 28.6% CDW. Based on maximum theoretical
yield calculations, E. coli is capable of producing 0.38 g
(R)-3-hydroxydodecanoic acid per g glucose fed. Thus, further
optimization of the described pathway for mcl-PHA biosynthesis
should lead to additional improvements in the yield on glucose as a
sole carbon source. For example, improvements in PHA biosynthesis
could be achieved through expression of alternative polymerases or
hydratases with a higher activity for C.sub.12 units. Besides fadJ
(yfcX), there exist at least five additional genes with homology to
fadB on the E. coli chromosome (Park and Lee, 2004). When these
genes were overexpressed in E. coli .DELTA.fadB in the presence of
a PHA polymerase and LB+0.2% decanoic acid (C.sub.10), a 1.3- to
2.0-fold improvement in PHA accumulation (% CDW) was achieved over
an empty vector control. Along with fadJ, overexpression of ydbU,
paaF and paaG resulted in the greatest improvement. By contrast, no
PHA accumulation was detected in E. coli fadB.sup.+ under the same
conditions. Therefore, these gene products may have a role in both
C.sub.12 metabolism and PHA biosynthesis in E. coli and
overexpression of these genes in addition to or in place of phaJ
could improve PHA accumulation.
Conclusions
[0165] The foregoing Examples present a scheme for producing
mcl-PHA homopolymer from a non-fatty acid related carbon source at
up to 17.3% CDW. Examination of a series of .beta.-oxidation
deletion strains provided an understanding of knockouts suitable to
completely inhibit iterative degradation of both exogenously fed
and endogenously produced fatty acids. Specifically, disruption of
both the aerobic and anaerobic pathways (i.e., fadBA or fadIJ)
proved suitable for the proposed mcl-PHA biosynthesis pathway.
Co-expression of phaJ3 and phaC2 from P. aeruginosa PAO1 in E. coli
.DELTA.fadRABIJ yielded polyhydroxydodecanoate in the presence of
dodecanoic acid feeding. When the plant acyl-ACP thioesterase, BTE,
was expressed in this strain, PHA comprised primarily of
hydroxydodecanoate monomers was observed. Finally, expression of an
additional, soluble CoA-synthetase improved production 5-fold
resulting in the highest reported production of mcl-PHA for a
scheme involving a thioesterase.
[0166] This strategy can be generalized to produce a variety of
mcl-PHA homo- and heteropolymers, where the resulting monomer
composition can be tailored based on the known fatty acid
production profile of a particular acyl-ACP thioesterase. If
integrated with pathways for converting renewable substrates to
acetyl-CoA, processes for synthesizing designer mcl-PHA can be
developed. The use of inexpensive feedstocks will ultimately allow
renewable, biodegradable PHAs to compete on a cost-basis with
analogous, petroleum derived plastics.
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G. Q., 2011. Biosynthesis of polyhydroxyalkanoate homopolymers by
Pseudomonas putida. Applied Microbiology and Biotechnology. 89,
1497-1507. [0205] Wang, Q., Tappel, R. C., Zhu, C. J., Nomura, C.
T., 2012. Development of a New Strategy for Production of
Medium-Chain-Length Polyhydroxyalkanoates by Recombinant
Escherichia coli via Inexpensive Non-Fatty Acid Feedstocks. Applied
and Environmental Microbiology. 78, 519-527. [0206] Youngquist, J.
T., Lennen, R. M., Ranatunga, D. R., Bothfeld, W. H., II, W. D. M.,
Pfleger, B. F., 2012. Kinetic modeling of free fatty acid
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Sequence CWU 1
1
5412190DNAEscherichia coli 1atgctttaca aaggcgacac cctgtacctt
gactggctgg aagatggcat tgccgaactg 60gtatttgatg ccccaggttc agttaataaa
ctcgacactg cgaccgtcgc cagcctcggc 120gaggccatcg gcgtgctgga
acagcaatca gatctaaaag ggctgctgct gcgttcgaac 180aaagcagcct
ttatcgtcgg tgctgatatc accgaatttt tgtccctgtt cctcgttcct
240gaagaacagt taagtcagtg gctgcacttt gccaatagcg tgtttaatcg
cctggaagat 300ctgccggtgc cgaccattgc tgccgtcaat ggctatgcgc
tgggcggtgg ctgcgaatgc 360gtgctggcga ccgattatcg tctggcgacg
ccggatctgc gcatcggtct gccggaaacc 420aaactgggca tcatgcctgg
ctttggcggt tctgtacgta tgccacgtat gctgggcgct 480gacagtgcgc
tggaaatcat tgccgccggt aaagatgtcg gcgcggatca ggcgctgaaa
540atcggtctgg tggatggcgt agtcaaagca gaaaaactgg ttgaaggcgc
aaaggcggtt 600ttacgccagg ccattaacgg cgacctcgac tggaaagcaa
aacgtcagcc gaagctggaa 660ccactaaaac tgagcaagat tgaagccacc
atgagcttca ccatcgctaa agggatggtc 720gcacaaacag cggggaaaca
ttatccggcc cccatcaccg cagtaaaaac cattgaagct 780gcggcccgtt
ttggtcgtga agaagcctta aacctggaaa acaaaagttt tgtcccgctg
840gcgcatacca acgaagcccg cgcactggtc ggcattttcc ttaacgatca
atatgtaaaa 900ggcaaagcga agaaactcac caaagacgtt gaaaccccga
aacaggccgc ggtgctgggt 960gcaggcatta tgggcggcgg catcgcttac
cagtctgcgt ggaaaggcgt gccggttgtc 1020atgaaagata tcaacgacaa
gtcgttaacc ctcggcatga ccgaagccgc gaaactgctg 1080aacaagcagc
ttgagcgcgg caagatcgat ggtctgaaac tggctggcgt gatctccaca
1140atccacccaa cgctcgacta cgccggattt gaccgcgtgg atattgtggt
agaagcggtt 1200gttgaaaacc cgaaagtgaa aaaagccgta ctggcagaaa
ccgaacaaaa agtacgccag 1260gataccgtgc tggcgtctaa cacttcaacc
attcctatca gcgaactggc caacgcgctg 1320gaacgcccgg aaaacttctg
cgggatgcac ttctttaacc cggtccaccg aatgccgttg 1380gtagaaatta
ttcgcggcga gaaaagctcc gacgaaacca tcgcgaaagt tgtcgcctgg
1440gcgagcaaga tgggcaagac gccgattgtg gttaacgact gccccggctt
ctttgttaac 1500cgcgtgctgt tcccgtattt cgccggtttc agccagctgc
tgcgcgacgg cgcggatttc 1560cgcaagatcg acaaagtgat ggaaaaacag
tttggctggc cgatgggccc ggcatatctg 1620ctggacgttg tgggcattga
taccgcgcat cacgctcagg ctgtcatggc agcaggcttc 1680ccgcagcgga
tgcagaaaga ttaccgcgat gccatcgacg cgctgtttga tgccaaccgc
1740tttggtcaga agaacggcct cggtttctgg cgttataaag aagacagcaa
aggtaagccg 1800aagaaagaag aagacgccgc cgttgaagac ctgctggcag
aagtgagcca gccgaagcgc 1860gatttcagcg aagaagagat tatcgcccgc
atgatgatcc cgatggtcaa cgaagtggtg 1920cgctgtctgg aggaaggcat
tatcgccact ccggcggaag cggatatggc gctggtctac 1980ggcctgggct
tccctccgtt ccacggcggc gcgttccgct ggctggacac cctcggtagc
2040gcaaaatacc tcgatatggc acagcaatat cagcacctcg gcccgctgta
tgaagtgccg 2100gaaggtctgc gtaataaagc gcgtcataac gaaccgtact
atcctccggt tgagccagcc 2160cgtccggttg gcgacctgaa aacggcttaa
21902729PRTEscherichia coli 2Met Leu Tyr Lys Gly Asp Thr Leu Tyr
Leu Asp Trp Leu Glu Asp Gly 1 5 10 15 Ile Ala Glu Leu Val Phe Asp
Ala Pro Gly Ser Val Asn Lys Leu Asp 20 25 30 Thr Ala Thr Val Ala
Ser Leu Gly Glu Ala Ile Gly Val Leu Glu Gln 35 40 45 Gln Ser Asp
Leu Lys Gly Leu Leu Leu Arg Ser Asn Lys Ala Ala Phe 50 55 60 Ile
Val Gly Ala Asp Ile Thr Glu Phe Leu Ser Leu Phe Leu Val Pro 65 70
75 80 Glu Glu Gln Leu Ser Gln Trp Leu His Phe Ala Asn Ser Val Phe
Asn 85 90 95 Arg Leu Glu Asp Leu Pro Val Pro Thr Ile Ala Ala Val
Asn Gly Tyr 100 105 110 Ala Leu Gly Gly Gly Cys Glu Cys Val Leu Ala
Thr Asp Tyr Arg Leu 115 120 125 Ala Thr Pro Asp Leu Arg Ile Gly Leu
Pro Glu Thr Lys Leu Gly Ile 130 135 140 Met Pro Gly Phe Gly Gly Ser
Val Arg Met Pro Arg Met Leu Gly Ala 145 150 155 160 Asp Ser Ala Leu
Glu Ile Ile Ala Ala Gly Lys Asp Val Gly Ala Asp 165 170 175 Gln Ala
Leu Lys Ile Gly Leu Val Asp Gly Val Val Lys Ala Glu Lys 180 185 190
Leu Val Glu Gly Ala Lys Ala Val Leu Arg Gln Ala Ile Asn Gly Asp 195
200 205 Leu Asp Trp Lys Ala Lys Arg Gln Pro Lys Leu Glu Pro Leu Lys
Leu 210 215 220 Ser Lys Ile Glu Ala Thr Met Ser Phe Thr Ile Ala Lys
Gly Met Val 225 230 235 240 Ala Gln Thr Ala Gly Lys His Tyr Pro Ala
Pro Ile Thr Ala Val Lys 245 250 255 Thr Ile Glu Ala Ala Ala Arg Phe
Gly Arg Glu Glu Ala Leu Asn Leu 260 265 270 Glu Asn Lys Ser Phe Val
Pro Leu Ala His Thr Asn Glu Ala Arg Ala 275 280 285 Leu Val Gly Ile
Phe Leu Asn Asp Gln Tyr Val Lys Gly Lys Ala Lys 290 295 300 Lys Leu
Thr Lys Asp Val Glu Thr Pro Lys Gln Ala Ala Val Leu Gly 305 310 315
320 Ala Gly Ile Met Gly Gly Gly Ile Ala Tyr Gln Ser Ala Trp Lys Gly
325 330 335 Val Pro Val Val Met Lys Asp Ile Asn Asp Lys Ser Leu Thr
Leu Gly 340 345 350 Met Thr Glu Ala Ala Lys Leu Leu Asn Lys Gln Leu
Glu Arg Gly Lys 355 360 365 Ile Asp Gly Leu Lys Leu Ala Gly Val Ile
Ser Thr Ile His Pro Thr 370 375 380 Leu Asp Tyr Ala Gly Phe Asp Arg
Val Asp Ile Val Val Glu Ala Val 385 390 395 400 Val Glu Asn Pro Lys
Val Lys Lys Ala Val Leu Ala Glu Thr Glu Gln 405 410 415 Lys Val Arg
Gln Asp Thr Val Leu Ala Ser Asn Thr Ser Thr Ile Pro 420 425 430 Ile
Ser Glu Leu Ala Asn Ala Leu Glu Arg Pro Glu Asn Phe Cys Gly 435 440
445 Met His Phe Phe Asn Pro Val His Arg Met Pro Leu Val Glu Ile Ile
450 455 460 Arg Gly Glu Lys Ser Ser Asp Glu Thr Ile Ala Lys Val Val
Ala Trp 465 470 475 480 Ala Ser Lys Met Gly Lys Thr Pro Ile Val Val
Asn Asp Cys Pro Gly 485 490 495 Phe Phe Val Asn Arg Val Leu Phe Pro
Tyr Phe Ala Gly Phe Ser Gln 500 505 510 Leu Leu Arg Asp Gly Ala Asp
Phe Arg Lys Ile Asp Lys Val Met Glu 515 520 525 Lys Gln Phe Gly Trp
Pro Met Gly Pro Ala Tyr Leu Leu Asp Val Val 530 535 540 Gly Ile Asp
Thr Ala His His Ala Gln Ala Val Met Ala Ala Gly Phe 545 550 555 560
Pro Gln Arg Met Gln Lys Asp Tyr Arg Asp Ala Ile Asp Ala Leu Phe 565
570 575 Asp Ala Asn Arg Phe Gly Gln Lys Asn Gly Leu Gly Phe Trp Arg
Tyr 580 585 590 Lys Glu Asp Ser Lys Gly Lys Pro Lys Lys Glu Glu Asp
Ala Ala Val 595 600 605 Glu Asp Leu Leu Ala Glu Val Ser Gln Pro Lys
Arg Asp Phe Ser Glu 610 615 620 Glu Glu Ile Ile Ala Arg Met Met Ile
Pro Met Val Asn Glu Val Val 625 630 635 640 Arg Cys Leu Glu Glu Gly
Ile Ile Ala Thr Pro Ala Glu Ala Asp Met 645 650 655 Ala Leu Val Tyr
Gly Leu Gly Phe Pro Pro Phe His Gly Gly Ala Phe 660 665 670 Arg Trp
Leu Asp Thr Leu Gly Ser Ala Lys Tyr Leu Asp Met Ala Gln 675 680 685
Gln Tyr Gln His Leu Gly Pro Leu Tyr Glu Val Pro Glu Gly Leu Arg 690
695 700 Asn Lys Ala Arg His Asn Glu Pro Tyr Tyr Pro Pro Val Glu Pro
Ala 705 710 715 720 Arg Pro Val Gly Asp Leu Lys Thr Ala 725
32145DNAEscherichia coli 3atggaaatga catcagcgtt tacccttaat
gttcgtctgg acaacattgc cgttatcacc 60atcgacgtac cgggtgagaa aatgaatacc
ctgaaggcgg agtttgcctc gcaggtgcgc 120gccattatta agcaactccg
tgaaaacaaa gagttgcgag gcgtggtgtt tgtctccgct 180aaaccggaca
acttcattgc tggcgcagac atcaacatga tcggcaactg caaaacggcg
240caagaagcgg aagctctggc gcggcagggc caacagttga tggcggagat
tcatgctttg 300cccattcagg ttatcgcggc tattcatggc gcttgcctgg
gtggtgggct ggagttggcg 360ctggcgtgcc acggtcgcgt ttgtactgac
gatcctaaaa cggtgctcgg tttgcctgaa 420gtacaacttg gattgttacc
cggttcaggc ggcacccagc gtttaccgcg tctgataggc 480gtcagcacag
cattagagat gatcctcacc ggaaaacaac ttcgggcgaa acaggcatta
540aagctggggc tggtggatga cgttgttccg cactccattc tgctggaagc
cgctgttgag 600ctggcaaaga aggagcgccc atcttcccgc cctctacctg
tacgcgagcg tattctggcg 660gggccgttag gtcgtgcgct gctgttcaaa
atggtcggca agaaaacaga acacaaaact 720caaggcaatt atccggcgac
agaacgcatc ctggaggttg ttgaaacggg attagcgcag 780ggcaccagca
gcggttatga cgccgaagct cgggcgtttg gcgaactggc gatgacgcca
840caatcgcagg cgctgcgtag tatctttttt gccagtacgg acgtgaagaa
agatcccggc 900agtgatgcgc cgcctgcgcc attaaacagc gtggggattt
taggtggtgg cttgatgggc 960ggcggtattg cttatgtcac tgcttgtaaa
gcggggattc cggtcagaat taaagatatc 1020aacccgcagg gcataaatca
tgcgctgaag tacagttggg atcagctgga gggcaaagtt 1080cgccgtcgtc
atctcaaagc cagcgaacgt gacaaacagc tggcattaat ctccggaacg
1140acggactatc gcggctttgc ccatcgcgat ctgattattg aagcggtgtt
tgaaaatctc 1200gaattgaaac aacagatggt ggcggaagtt gagcaaaatt
gcgccgctca taccatcttt 1260gcttcgaata cgtcatcttt accgattggt
gatatcgccg ctcacgccac gcgacctgag 1320caagttatcg gcctgcattt
cttcagtccg gtggaaaaaa tgccgctggt ggagattatt 1380cctcatgcgg
ggacatcggc gcaaaccatc gctaccacag taaaactggc gaaaaaacag
1440ggtaaaacgc caattgtcgt gcgtgacaaa gccggttttt acgtcaatcg
catcttagcg 1500ccttacatta atgaagctat ccgcatgttg acccaaggtg
aacgggtaga gcacattgat 1560gccgcgctag tgaaatttgg ttttccggta
ggcccaatcc aacttttgga tgaggtagga 1620atcgacaccg ggactaaaat
tattcctgta ctggaagccg cttatggaga acgttttagc 1680gcgcctgcaa
atgttgtttc ttcaattttg aacgacgatc gcaaaggcag aaaaaatggc
1740cggggtttct atctttatgg tcagaaaggg cgtaaaagca aaaaacaggt
cgatcccgcc 1800atttacccgc tgattggcac acaagggcag gggcgaatct
ccgcaccgca ggttgctgaa 1860cggtgtgtga tgttgatgct gaatgaagca
gtacgttgtg ttgatgagca ggttatccgt 1920agcgtgcgtg acggggatat
tggcgcggta tttggcattg gttttccgcc atttctcggt 1980ggaccgttcc
gctatatcga ttctctcggc gcgggcgaag tggttgcaat aatgcaacga
2040cttgccacgc agtatggttc ccgttttacc ccttgcgagc gtttggtcga
gatgggcgcg 2100cgtggggaaa gtttttggaa aacaactgca actgacctgc aataa
21454714PRTEscherichia coli 4Met Glu Met Thr Ser Ala Phe Thr Leu
Asn Val Arg Leu Asp Asn Ile 1 5 10 15 Ala Val Ile Thr Ile Asp Val
Pro Gly Glu Lys Met Asn Thr Leu Lys 20 25 30 Ala Glu Phe Ala Ser
Gln Val Arg Ala Ile Ile Lys Gln Leu Arg Glu 35 40 45 Asn Lys Glu
Leu Arg Gly Val Val Phe Val Ser Ala Lys Pro Asp Asn 50 55 60 Phe
Ile Ala Gly Ala Asp Ile Asn Met Ile Gly Asn Cys Lys Thr Ala 65 70
75 80 Gln Glu Ala Glu Ala Leu Ala Arg Gln Gly Gln Gln Leu Met Ala
Glu 85 90 95 Ile His Ala Leu Pro Ile Gln Val Ile Ala Ala Ile His
Gly Ala Cys 100 105 110 Leu Gly Gly Gly Leu Glu Leu Ala Leu Ala Cys
His Gly Arg Val Cys 115 120 125 Thr Asp Asp Pro Lys Thr Val Leu Gly
Leu Pro Glu Val Gln Leu Gly 130 135 140 Leu Leu Pro Gly Ser Gly Gly
Thr Gln Arg Leu Pro Arg Leu Ile Gly 145 150 155 160 Val Ser Thr Ala
Leu Glu Met Ile Leu Thr Gly Lys Gln Leu Arg Ala 165 170 175 Lys Gln
Ala Leu Lys Leu Gly Leu Val Asp Asp Val Val Pro His Ser 180 185 190
Ile Leu Leu Glu Ala Ala Val Glu Leu Ala Lys Lys Glu Arg Pro Ser 195
200 205 Ser Arg Pro Leu Pro Val Arg Glu Arg Ile Leu Ala Gly Pro Leu
Gly 210 215 220 Arg Ala Leu Leu Phe Lys Met Val Gly Lys Lys Thr Glu
His Lys Thr 225 230 235 240 Gln Gly Asn Tyr Pro Ala Thr Glu Arg Ile
Leu Glu Val Val Glu Thr 245 250 255 Gly Leu Ala Gln Gly Thr Ser Ser
Gly Tyr Asp Ala Glu Ala Arg Ala 260 265 270 Phe Gly Glu Leu Ala Met
Thr Pro Gln Ser Gln Ala Leu Arg Ser Ile 275 280 285 Phe Phe Ala Ser
Thr Asp Val Lys Lys Asp Pro Gly Ser Asp Ala Pro 290 295 300 Pro Ala
Pro Leu Asn Ser Val Gly Ile Leu Gly Gly Gly Leu Met Gly 305 310 315
320 Gly Gly Ile Ala Tyr Val Thr Ala Cys Lys Ala Gly Ile Pro Val Arg
325 330 335 Ile Lys Asp Ile Asn Pro Gln Gly Ile Asn His Ala Leu Lys
Tyr Ser 340 345 350 Trp Asp Gln Leu Glu Gly Lys Val Arg Arg Arg His
Leu Lys Ala Ser 355 360 365 Glu Arg Asp Lys Gln Leu Ala Leu Ile Ser
Gly Thr Thr Asp Tyr Arg 370 375 380 Gly Phe Ala His Arg Asp Leu Ile
Ile Glu Ala Val Phe Glu Asn Leu 385 390 395 400 Glu Leu Lys Gln Gln
Met Val Ala Glu Val Glu Gln Asn Cys Ala Ala 405 410 415 His Thr Ile
Phe Ala Ser Asn Thr Ser Ser Leu Pro Ile Gly Asp Ile 420 425 430 Ala
Ala His Ala Thr Arg Pro Glu Gln Val Ile Gly Leu His Phe Phe 435 440
445 Ser Pro Val Glu Lys Met Pro Leu Val Glu Ile Ile Pro His Ala Gly
450 455 460 Thr Ser Ala Gln Thr Ile Ala Thr Thr Val Lys Leu Ala Lys
Lys Gln 465 470 475 480 Gly Lys Thr Pro Ile Val Val Arg Asp Lys Ala
Gly Phe Tyr Val Asn 485 490 495 Arg Ile Leu Ala Pro Tyr Ile Asn Glu
Ala Ile Arg Met Leu Thr Gln 500 505 510 Gly Glu Arg Val Glu His Ile
Asp Ala Ala Leu Val Lys Phe Gly Phe 515 520 525 Pro Val Gly Pro Ile
Gln Leu Leu Asp Glu Val Gly Ile Asp Thr Gly 530 535 540 Thr Lys Ile
Ile Pro Val Leu Glu Ala Ala Tyr Gly Glu Arg Phe Ser 545 550 555 560
Ala Pro Ala Asn Val Val Ser Ser Ile Leu Asn Asp Asp Arg Lys Gly 565
570 575 Arg Lys Asn Gly Arg Gly Phe Tyr Leu Tyr Gly Gln Lys Gly Arg
Lys 580 585 590 Ser Lys Lys Gln Val Asp Pro Ala Ile Tyr Pro Leu Ile
Gly Thr Gln 595 600 605 Gly Gln Gly Arg Ile Ser Ala Pro Gln Val Ala
Glu Arg Cys Val Met 610 615 620 Leu Met Leu Asn Glu Ala Val Arg Cys
Val Asp Glu Gln Val Ile Arg 625 630 635 640 Ser Val Arg Asp Gly Asp
Ile Gly Ala Val Phe Gly Ile Gly Phe Pro 645 650 655 Pro Phe Leu Gly
Gly Pro Phe Arg Tyr Ile Asp Ser Leu Gly Ala Gly 660 665 670 Glu Val
Val Ala Ile Met Gln Arg Leu Ala Thr Gln Tyr Gly Ser Arg 675 680 685
Phe Thr Pro Cys Glu Arg Leu Val Glu Met Gly Ala Arg Gly Glu Ser 690
695 700 Phe Trp Lys Thr Thr Ala Thr Asp Leu Gln 705 710
51164DNAEscherichia coli 5atggaacagg ttgtcattgt cgatgcaatt
cgcaccccga tgggccgttc gaagggcggt 60gcttttcgta acgtgcgtgc agaagatctc
tccgctcatt taatgcgtag cctgctggcg 120cgtaacccgg cgctggaagc
ggcggccctc gacgatattt actggggttg tgtgcagcag 180acgctggagc
agggttttaa tatcgcccgt aacgcggcgc tgctggcaga agtaccacac
240tctgtcccgg cggttaccgt taatcgcttg tgtggttcat ccatgcaggc
actgcatgac 300gcagcacgaa tgatcatgac tggcgatgcg caggcatgtc
tggttggcgg cgtggagcat 360atgggccatg tgccgatgag tcacggcgtc
gattttcacc ccggcctgag ccgcaatgtc 420gccaaagcgg cgggcatgat
gggcttaacg gcagaaatgc tggcgcgtat gcacggtatc 480agccgtgaaa
tgcaggatgc ctttgccgcg cggtcacacg cccgcgcctg ggccgccacg
540cagtcggccg catttaaaaa tgaaatcatc ccgaccggtg gtcacgatgc
cgacggcgtc 600ctgaagcagt ttaattacga cgaagtgatt cgcccggaaa
ccaccgtgga agccctcgcc 660acgctgcgtc cggcgtttga tccagtaaac
ggtatggtaa cggcgggcac atcttctgca 720ctttccgatg gcgcagctgc
catgctggtg atgagtgaaa gccgcgccca tgaattaggt 780cttaagccgc
gcgctcgtgt gcgttcgatg gcggtcgttg gttgtgaccc atcgattatg
840ggttacggcc cggttccggc ctcgaaactg gcgctgaaaa aagcggggct
ttctgccagc 900gatatcggcg tgtttgaaat gaacgaagcc tttgccgcgc
agatcctgcc atgtattaaa 960gatctgggac taattgagca gattgacgag
aagatcaacc tcaacggtgg cgcgatcgcg 1020ctgggtcatc cgctgggttg
ttccggtgcg cgtatcagca ccacgctgct gaatctgatg 1080gaacgcaaag
acgttcagtt tggtctggcg acgatgtgta tcggtctggg tcagggtatt
1140gcgacggtgt
ttgagcgggt ttaa 11646387PRTEscherichia coli 6Met Glu Gln Val Val
Ile Val Asp Ala Ile Arg Thr Pro Met Gly Arg 1 5 10 15 Ser Lys Gly
Gly Ala Phe Arg Asn Val Arg Ala Glu Asp Leu Ser Ala 20 25 30 His
Leu Met Arg Ser Leu Leu Ala Arg Asn Pro Ala Leu Glu Ala Ala 35 40
45 Ala Leu Asp Asp Ile Tyr Trp Gly Cys Val Gln Gln Thr Leu Glu Gln
50 55 60 Gly Phe Asn Ile Ala Arg Asn Ala Ala Leu Leu Ala Glu Val
Pro His 65 70 75 80 Ser Val Pro Ala Val Thr Val Asn Arg Leu Cys Gly
Ser Ser Met Gln 85 90 95 Ala Leu His Asp Ala Ala Arg Met Ile Met
Thr Gly Asp Ala Gln Ala 100 105 110 Cys Leu Val Gly Gly Val Glu His
Met Gly His Val Pro Met Ser His 115 120 125 Gly Val Asp Phe His Pro
Gly Leu Ser Arg Asn Val Ala Lys Ala Ala 130 135 140 Gly Met Met Gly
Leu Thr Ala Glu Met Leu Ala Arg Met His Gly Ile 145 150 155 160 Ser
Arg Glu Met Gln Asp Ala Phe Ala Ala Arg Ser His Ala Arg Ala 165 170
175 Trp Ala Ala Thr Gln Ser Ala Ala Phe Lys Asn Glu Ile Ile Pro Thr
180 185 190 Gly Gly His Asp Ala Asp Gly Val Leu Lys Gln Phe Asn Tyr
Asp Glu 195 200 205 Val Ile Arg Pro Glu Thr Thr Val Glu Ala Leu Ala
Thr Leu Arg Pro 210 215 220 Ala Phe Asp Pro Val Asn Gly Met Val Thr
Ala Gly Thr Ser Ser Ala 225 230 235 240 Leu Ser Asp Gly Ala Ala Ala
Met Leu Val Met Ser Glu Ser Arg Ala 245 250 255 His Glu Leu Gly Leu
Lys Pro Arg Ala Arg Val Arg Ser Met Ala Val 260 265 270 Val Gly Cys
Asp Pro Ser Ile Met Gly Tyr Gly Pro Val Pro Ala Ser 275 280 285 Lys
Leu Ala Leu Lys Lys Ala Gly Leu Ser Ala Ser Asp Ile Gly Val 290 295
300 Phe Glu Met Asn Glu Ala Phe Ala Ala Gln Ile Leu Pro Cys Ile Lys
305 310 315 320 Asp Leu Gly Leu Ile Glu Gln Ile Asp Glu Lys Ile Asn
Leu Asn Gly 325 330 335 Gly Ala Ile Ala Leu Gly His Pro Leu Gly Cys
Ser Gly Ala Arg Ile 340 345 350 Ser Thr Thr Leu Leu Asn Leu Met Glu
Arg Lys Asp Val Gln Phe Gly 355 360 365 Leu Ala Thr Met Cys Ile Gly
Leu Gly Gln Gly Ile Ala Thr Val Phe 370 375 380 Glu Arg Val 385
71311DNAEscherichia coli 7atgggtcagg ttttaccgct ggttacccgc
cagggcgatc gtatcgccat tgttagcggt 60ttacgtacgc cttttgcccg tcaggcgacg
gcttttcatg gcattcccgc ggttgattta 120gggaagatgg tggtaggcga
actgctggca cgcagcgaga tccccgccga agtgattgaa 180caactggtct
ttggtcaggt cgtacaaatg cctgaagccc ccaacattgc gcgtgaaatt
240gttctcggta cgggaatgaa tgtacatacc gatgcttaca gcgtcagccg
cgcttgcgct 300accagtttcc aggcagttgc aaacgtcgca gaaagcctga
tggcgggaac tattcgagcg 360gggattgccg gtggggcaga ttcctcttcg
gtattgccaa ttggcgtcag taaaaaactg 420gcgcgcgtgc tggttgatgt
caacaaagct cgtaccatga gccagcgact gaaactcttc 480tctcgcctgc
gtttgcgcga cttaatgccc gtaccacctg cggtagcaga atattctacc
540ggcttgcgga tgggcgacac cgcagagcaa atggcgaaaa cctacggcat
cacccgagaa 600cagcaagatg cattagcgca ccgttcgcat cagcgtgccg
ctcaggcatg gtcagacgga 660aaactcaaag aagaggtgat gactgccttt
atccctcctt ataaacaacc gcttgtcgaa 720gacaacaata ttcgcggtaa
ttcctcgctt gccgattacg caaagctgcg cccggcgttt 780gatcgcaaac
acggaacggt aacggcggca aacagtacgc cgctgaccga tggcgcggca
840gcggtgatcc tgatgactga atcccgggcg aaagaattag ggctggtgcc
gctggggtat 900ctgcgcagct acgcatttac tgcgattgat gtctggcagg
acatgttgct cggtccagcc 960tggtcaacac cgctggcgct ggagcgtgcc
ggtttgacga tgagcgatct gacattgatc 1020gatatgcacg aagcctttgc
agctcagacg ctggcgaata ttcagttgct gggtagtgaa 1080cgttttgctc
gtgaagcact ggggcgtgca catgccactg gcgaagtgga cgatagcaaa
1140tttaacgtgc ttggcggttc gattgcttac gggcatccct tcgcggcgac
cggcgcgcgg 1200atgattaccc agacattgca tgaacttcgc cgtcgcggcg
gtggatttgg tttagttacc 1260gcctgtgctg ccggtgggct tggcgcggca
atggttctgg aggcggaata a 13118436PRTEscherichia coli 8Met Gly Gln
Val Leu Pro Leu Val Thr Arg Gln Gly Asp Arg Ile Ala 1 5 10 15 Ile
Val Ser Gly Leu Arg Thr Pro Phe Ala Arg Gln Ala Thr Ala Phe 20 25
30 His Gly Ile Pro Ala Val Asp Leu Gly Lys Met Val Val Gly Glu Leu
35 40 45 Leu Ala Arg Ser Glu Ile Pro Ala Glu Val Ile Glu Gln Leu
Val Phe 50 55 60 Gly Gln Val Val Gln Met Pro Glu Ala Pro Asn Ile
Ala Arg Glu Ile 65 70 75 80 Val Leu Gly Thr Gly Met Asn Val His Thr
Asp Ala Tyr Ser Val Ser 85 90 95 Arg Ala Cys Ala Thr Ser Phe Gln
Ala Val Ala Asn Val Ala Glu Ser 100 105 110 Leu Met Ala Gly Thr Ile
Arg Ala Gly Ile Ala Gly Gly Ala Asp Ser 115 120 125 Ser Ser Val Leu
Pro Ile Gly Val Ser Lys Lys Leu Ala Arg Val Leu 130 135 140 Val Asp
Val Asn Lys Ala Arg Thr Met Ser Gln Arg Leu Lys Leu Phe 145 150 155
160 Ser Arg Leu Arg Leu Arg Asp Leu Met Pro Val Pro Pro Ala Val Ala
165 170 175 Glu Tyr Ser Thr Gly Leu Arg Met Gly Asp Thr Ala Glu Gln
Met Ala 180 185 190 Lys Thr Tyr Gly Ile Thr Arg Glu Gln Gln Asp Ala
Leu Ala His Arg 195 200 205 Ser His Gln Arg Ala Ala Gln Ala Trp Ser
Asp Gly Lys Leu Lys Glu 210 215 220 Glu Val Met Thr Ala Phe Ile Pro
Pro Tyr Lys Gln Pro Leu Val Glu 225 230 235 240 Asp Asn Asn Ile Arg
Gly Asn Ser Ser Leu Ala Asp Tyr Ala Lys Leu 245 250 255 Arg Pro Ala
Phe Asp Arg Lys His Gly Thr Val Thr Ala Ala Asn Ser 260 265 270 Thr
Pro Leu Thr Asp Gly Ala Ala Ala Val Ile Leu Met Thr Glu Ser 275 280
285 Arg Ala Lys Glu Leu Gly Leu Val Pro Leu Gly Tyr Leu Arg Ser Tyr
290 295 300 Ala Phe Thr Ala Ile Asp Val Trp Gln Asp Met Leu Leu Gly
Pro Ala 305 310 315 320 Trp Ser Thr Pro Leu Ala Leu Glu Arg Ala Gly
Leu Thr Met Ser Asp 325 330 335 Leu Thr Leu Ile Asp Met His Glu Ala
Phe Ala Ala Gln Thr Leu Ala 340 345 350 Asn Ile Gln Leu Leu Gly Ser
Glu Arg Phe Ala Arg Glu Ala Leu Gly 355 360 365 Arg Ala His Ala Thr
Gly Glu Val Asp Asp Ser Lys Phe Asn Val Leu 370 375 380 Gly Gly Ser
Ile Ala Tyr Gly His Pro Phe Ala Ala Thr Gly Ala Arg 385 390 395 400
Met Ile Thr Gln Thr Leu His Glu Leu Arg Arg Arg Gly Gly Gly Phe 405
410 415 Gly Leu Val Thr Ala Cys Ala Ala Gly Gly Leu Gly Ala Ala Met
Val 420 425 430 Leu Glu Ala Glu 435 9720DNAEscherichia coli
9atggtcatta aggcgcaaag cccggcgggt ttcgcggaag agtacattat tgaaagtatc
60tggaataacc gcttccctcc cgggactatt ttgcccgcag aacgtgaact ttcagaatta
120attggcgtaa cgcgtactac gttacgtgaa gtgttacagc gtctggcacg
agatggctgg 180ttgaccattc aacatggcaa gccgacgaag gtgaataatt
tctgggaaac ttccggttta 240aatatccttg aaacactggc gcgactggat
cacgaaagtg tgccgcagct tattgataat 300ttgctgtcgg tgcgtaccaa
tatttccact atttttattc gcaccgcgtt tcgtcagcat 360cccgataaag
cgcaggaagt gctggctacc gctaatgaag tggccgatca cgccgatgcc
420tttgccgagc tggattacaa catattccgc ggcctggcgt ttgcttccgg
caacccgatt 480tacggtctga ttcttaacgg gatgaaaggg ctgtatacgc
gtattggtcg tcactatttc 540gccaatccgg aagcgcgcag tctggcgctg
ggcttctacc acaaactgtc ggcgttgtgc 600agtgaaggcg cgcacgatca
ggtgtacgaa acagtgcgtc gctatgggca tgagagtggc 660gagatttggc
accggatgca gaaaaatctg ccgggtgatt tagccattca ggggcgataa
72010239PRTEscherichia coli 10Met Val Ile Lys Ala Gln Ser Pro Ala
Gly Phe Ala Glu Glu Tyr Ile 1 5 10 15 Ile Glu Ser Ile Trp Asn Asn
Arg Phe Pro Pro Gly Thr Ile Leu Pro 20 25 30 Ala Glu Arg Glu Leu
Ser Glu Leu Ile Gly Val Thr Arg Thr Thr Leu 35 40 45 Arg Glu Val
Leu Gln Arg Leu Ala Arg Asp Gly Trp Leu Thr Ile Gln 50 55 60 His
Gly Lys Pro Thr Lys Val Asn Asn Phe Trp Glu Thr Ser Gly Leu 65 70
75 80 Asn Ile Leu Glu Thr Leu Ala Arg Leu Asp His Glu Ser Val Pro
Gln 85 90 95 Leu Ile Asp Asn Leu Leu Ser Val Arg Thr Asn Ile Ser
Thr Ile Phe 100 105 110 Ile Arg Thr Ala Phe Arg Gln His Pro Asp Lys
Ala Gln Glu Val Leu 115 120 125 Ala Thr Ala Asn Glu Val Ala Asp His
Ala Asp Ala Phe Ala Glu Leu 130 135 140 Asp Tyr Asn Ile Phe Arg Gly
Leu Ala Phe Ala Ser Gly Asn Pro Ile 145 150 155 160 Tyr Gly Leu Ile
Leu Asn Gly Met Lys Gly Leu Tyr Thr Arg Ile Gly 165 170 175 Arg His
Tyr Phe Ala Asn Pro Glu Ala Arg Ser Leu Ala Leu Gly Phe 180 185 190
Tyr His Lys Leu Ser Ala Leu Cys Ser Glu Gly Ala His Asp Gln Val 195
200 205 Tyr Glu Thr Val Arg Arg Tyr Gly His Glu Ser Gly Glu Ile Trp
His 210 215 220 Arg Met Gln Lys Asn Leu Pro Gly Asp Leu Ala Ile Gln
Gly Arg 225 230 235 111686DNAEscherichia coli 11ttgaagaagg
tttggcttaa ccgttatccc gcggacgttc cgacggagat caaccctgac 60cgttatcaat
ctctggtaga tatgtttgag cagtcggtcg cgcgctacgc cgatcaacct
120gcgtttgtga atatggggga ggtaatgacc ttccgcaagc tggaagaacg
cagtcgcgcg 180tttgccgctt atttgcaaca agggttgggg ctgaagaaag
gcgatcgcgt tgcgttgatg 240atgcctaatt tattgcaata tccggtggcg
ctgtttggca ttttgcgtgc cgggatgatc 300gtcgtaaacg ttaacccgtt
gtataccccg cgtgagcttg agcatcagct taacgatagc 360ggcgcatcgg
cgattgttat cgtgtctaac tttgctcaca cactggaaaa agtggttgat
420aaaaccgccg ttcagcacgt aattctgacc cgtatgggcg atcagctatc
tacggcaaaa 480ggcacggtag tcaatttcgt tgttaaatac atcaagcgtt
tggtgccgaa ataccatctg 540ccagatgcca tttcatttcg tagcgcactg
cataacggct accggatgca gtacgtcaaa 600cccgaactgg tgccggaaga
tttagctttt ctgcaataca ccggcggcac cactggtgtg 660gcgaaaggcg
cgatgctgac tcaccgcaat atgctggcga acctggaaca ggttaacgcg
720acctatggtc cgctgttgca tccgggcaaa gagctggtgg tgacggcgct
gccgctgtat 780cacatttttg ccctgaccat taactgcctg ctgtttatcg
aactgggtgg gcagaacctg 840cttatcacta acccgcgcga tattccaggg
ttggtaaaag agttagcgaa atatccgttt 900accgctatca cgggcgttaa
caccttgttc aatgcgttgc tgaacaataa agagttccag 960cagctggatt
tctccagtct gcatctttcc gcaggcggtg ggatgccagt gcagcaagtg
1020gtggcagagc gttgggtgaa actgaccgga cagtatctgc tggaaggcta
tggccttacc 1080gagtgtgcgc cgctggtcag cgttaaccca tatgatattg
attatcatag tggtagcatc 1140ggtttgccgg tgccgtcgac ggaagccaaa
ctggtggatg atgatgataa tgaagtacca 1200ccaggtcaac cgggtgagct
ttgtgtcaaa ggaccgcagg tgatgctggg ttactggcag 1260cgtcccgatg
ctaccgatga aatcatcaaa aatggctggt tacacaccgg cgacatcgcg
1320gtaatggatg aagaaggatt cctgcgcatt gtcgatcgta aaaaagacat
gattctggtt 1380tccggtttta acgtctatcc caacgagatt gaagatgtcg
tcatgcagca tcctggcgta 1440caggaagtcg cggctgttgg cgtaccttcc
ggctccagtg gtgaagcggt gaaaatcttc 1500gtagtgaaaa aagatccatc
gcttaccgaa gagtcactgg tgactttttg ccgccgtcag 1560ctcacgggat
acaaagtacc gaagctggtg gagtttcgtg atgagttacc gaaatctaac
1620gtcggaaaaa ttttgcgacg agaattacgt gacgaagcgc gcggcaaagt
ggacaataaa 1680gcctga 168612561PRTEscherichia coli 12Met Lys Lys
Val Trp Leu Asn Arg Tyr Pro Ala Asp Val Pro Thr Glu 1 5 10 15 Ile
Asn Pro Asp Arg Tyr Gln Ser Leu Val Asp Met Phe Glu Gln Ser 20 25
30 Val Ala Arg Tyr Ala Asp Gln Pro Ala Phe Val Asn Met Gly Glu Val
35 40 45 Met Thr Phe Arg Lys Leu Glu Glu Arg Ser Arg Ala Phe Ala
Ala Tyr 50 55 60 Leu Gln Gln Gly Leu Gly Leu Lys Lys Gly Asp Arg
Val Ala Leu Met 65 70 75 80 Met Pro Asn Leu Leu Gln Tyr Pro Val Ala
Leu Phe Gly Ile Leu Arg 85 90 95 Ala Gly Met Ile Val Val Asn Val
Asn Pro Leu Tyr Thr Pro Arg Glu 100 105 110 Leu Glu His Gln Leu Asn
Asp Ser Gly Ala Ser Ala Ile Val Ile Val 115 120 125 Ser Asn Phe Ala
His Thr Leu Glu Lys Val Val Asp Lys Thr Ala Val 130 135 140 Gln His
Val Ile Leu Thr Arg Met Gly Asp Gln Leu Ser Thr Ala Lys 145 150 155
160 Gly Thr Val Val Asn Phe Val Val Lys Tyr Ile Lys Arg Leu Val Pro
165 170 175 Lys Tyr His Leu Pro Asp Ala Ile Ser Phe Arg Ser Ala Leu
His Asn 180 185 190 Gly Tyr Arg Met Gln Tyr Val Lys Pro Glu Leu Val
Pro Glu Asp Leu 195 200 205 Ala Phe Leu Gln Tyr Thr Gly Gly Thr Thr
Gly Val Ala Lys Gly Ala 210 215 220 Met Leu Thr His Arg Asn Met Leu
Ala Asn Leu Glu Gln Val Asn Ala 225 230 235 240 Thr Tyr Gly Pro Leu
Leu His Pro Gly Lys Glu Leu Val Val Thr Ala 245 250 255 Leu Pro Leu
Tyr His Ile Phe Ala Leu Thr Ile Asn Cys Leu Leu Phe 260 265 270 Ile
Glu Leu Gly Gly Gln Asn Leu Leu Ile Thr Asn Pro Arg Asp Ile 275 280
285 Pro Gly Leu Val Lys Glu Leu Ala Lys Tyr Pro Phe Thr Ala Ile Thr
290 295 300 Gly Val Asn Thr Leu Phe Asn Ala Leu Leu Asn Asn Lys Glu
Phe Gln 305 310 315 320 Gln Leu Asp Phe Ser Ser Leu His Leu Ser Ala
Gly Gly Gly Met Pro 325 330 335 Val Gln Gln Val Val Ala Glu Arg Trp
Val Lys Leu Thr Gly Gln Tyr 340 345 350 Leu Leu Glu Gly Tyr Gly Leu
Thr Glu Cys Ala Pro Leu Val Ser Val 355 360 365 Asn Pro Tyr Asp Ile
Asp Tyr His Ser Gly Ser Ile Gly Leu Pro Val 370 375 380 Pro Ser Thr
Glu Ala Lys Leu Val Asp Asp Asp Asp Asn Glu Val Pro 385 390 395 400
Pro Gly Gln Pro Gly Glu Leu Cys Val Lys Gly Pro Gln Val Met Leu 405
410 415 Gly Tyr Trp Gln Arg Pro Asp Ala Thr Asp Glu Ile Ile Lys Asn
Gly 420 425 430 Trp Leu His Thr Gly Asp Ile Ala Val Met Asp Glu Glu
Gly Phe Leu 435 440 445 Arg Ile Val Asp Arg Lys Lys Asp Met Ile Leu
Val Ser Gly Phe Asn 450 455 460 Val Tyr Pro Asn Glu Ile Glu Asp Val
Val Met Gln His Pro Gly Val 465 470 475 480 Gln Glu Val Ala Ala Val
Gly Val Pro Ser Gly Ser Ser Gly Glu Ala 485 490 495 Val Lys Ile Phe
Val Val Lys Lys Asp Pro Ser Leu Thr Glu Glu Ser 500 505 510 Leu Val
Thr Phe Cys Arg Arg Gln Leu Thr Gly Tyr Lys Val Pro Lys 515 520 525
Leu Val Glu Phe Arg Asp Glu Leu Pro Lys Ser Asn Val Gly Lys Ile 530
535 540 Leu Arg Arg Glu Leu Arg Asp Glu Ala Arg Gly Lys Val Asp Asn
Lys 545 550 555 560 Ala 131683DNAPseudomonas putida 13atgttgcaga
cacgcatcat caagcccgcc gagggcgcct atgcctatcc attgctgatc 60aagcgcctgc
tgatgtccgg cagccgctat gaaaagaccc gggaaatcgt ctaccgcgac
120cagatgcggc tgacgtatcc acagctcaac gagcgcattg cccgcctggc
caacgtgctg 180accgaggccg gggtcaaggc cggtgacacc gtggcggtga
tggactggga cagccatcgc 240tacctggaat gcatgttcgc catcccgatg
atcggcgctg tggtgcacac catcaacgtg 300cgcctgtcgc ccgagcagat
cctctacacc atgaaccatg ccgaagaccg cgtggtgctg 360gtcaacagcg
acttcgtcgg cctgtaccag gccatcgccg ggcagctgac cactgtcgac
420aagaccctgc tactgaccga tggcccggac aagactgccg aactgcccgg
tctggtcggc 480gagtatgagc agctgctggc tgctgccagc ccgcgctacg
acttcccgga tttcgacgag 540aattcggtgg ccactacctt ctacaccact
ggcaccaccg gtaaccccaa gggcgtgtat 600ttcagtcacc gccagctggt
gctgcacacc ctggccgagg cctcggtcac cggcagtatc 660gacagcgtgc
gcctgctggg cagcaacgat gtgtacatgc ccatcacccc gatgttccac
720gtgcatgcct ggggcatccc ctacgctgcc accatgctcg gcatgaagca
ggtgtaccca 780gggcgctacg agccggacat gctggtcaag ctttggcgtg
aagagaaggt cactttctcc 840cactgcgtgc cgaccatcct gcagatgctg
ctcaactgcc cgaacgccca ggggcaggac 900ttcggcggct ggaagatcat
catcggcggc agctcgctca accgttcgct gtaccaggcc 960gccctggcgc
gcggcatcca gctgaccgcc gcgtatggca tgtcggaaac ctgcccgctg
1020atctccgcgg cacacctgaa cgatgaactg caggccggca gcgaggatga
gcgcgtcact 1080taccgtatca aggccggtgt gccggtgccg ttggtcgaag
cggccatcgt cgacggcgaa 1140ggcaacttcc tgcccgccga tggtgaaacc
cagggcgagc tggtactgcg tgcgccgtgg 1200ctgaccatgg gctacttcaa
ggagccggag aagagcgagg agctgtggca gggcggctgg 1260ctgcacaccg
gtgacgtcgc caccctcgac ggcatgggct acatcgacat ccgcgaccgc
1320atcaaggatg tgatcaagac cggtggcgag tgggtttcct cgctcgacct
ggaagacctg 1380atcagccgcc acccggccgt gcgcgaagtg gcggtggtgg
gggtggccga cccgcagtgg 1440ggtgagcgcc cgtttgccct gctggtggca
cgtgacggcc acgatatcga cgccaaggcg 1500ctgaaggaac acctcaagcc
attcgtcgag caaggtcata tcaacaagtg ggcgattcca 1560agccagatcg
cccttgttac tgaaattccc aagaccagtg tcggcaagct cgacaagaaa
1620cgcattcgcc aggacatcgt ccagtggcag gccagcaaca gcgcgttcct
ttccacgttg 1680taa 168314560PRTPseudomonas putida 14Met Leu Gln Thr
Arg Ile Ile Lys Pro Ala Glu Gly Ala Tyr Ala Tyr 1 5 10 15 Pro Leu
Leu Ile Lys Arg Leu Leu Met Ser Gly Ser Arg Tyr Glu Lys 20 25 30
Thr Arg Glu Ile Val Tyr Arg Asp Gln Met Arg Leu Thr Tyr Pro Gln 35
40 45 Leu Asn Glu Arg Ile Ala Arg Leu Ala Asn Val Leu Thr Glu Ala
Gly 50 55 60 Val Lys Ala Gly Asp Thr Val Ala Val Met Asp Trp Asp
Ser His Arg 65 70 75 80 Tyr Leu Glu Cys Met Phe Ala Ile Pro Met Ile
Gly Ala Val Val His 85 90 95 Thr Ile Asn Val Arg Leu Ser Pro Glu
Gln Ile Leu Tyr Thr Met Asn 100 105 110 His Ala Glu Asp Arg Val Val
Leu Val Asn Ser Asp Phe Val Gly Leu 115 120 125 Tyr Gln Ala Ile Ala
Gly Gln Leu Thr Thr Val Asp Lys Thr Leu Leu 130 135 140 Leu Thr Asp
Gly Pro Asp Lys Thr Ala Glu Leu Pro Gly Leu Val Gly 145 150 155 160
Glu Tyr Glu Gln Leu Leu Ala Ala Ala Ser Pro Arg Tyr Asp Phe Pro 165
170 175 Asp Phe Asp Glu Asn Ser Val Ala Thr Thr Phe Tyr Thr Thr Gly
Thr 180 185 190 Thr Gly Asn Pro Lys Gly Val Tyr Phe Ser His Arg Gln
Leu Val Leu 195 200 205 His Thr Leu Ala Glu Ala Ser Val Thr Gly Ser
Ile Asp Ser Val Arg 210 215 220 Leu Leu Gly Ser Asn Asp Val Tyr Met
Pro Ile Thr Pro Met Phe His 225 230 235 240 Val His Ala Trp Gly Ile
Pro Tyr Ala Ala Thr Met Leu Gly Met Lys 245 250 255 Gln Val Tyr Pro
Gly Arg Tyr Glu Pro Asp Met Leu Val Lys Leu Trp 260 265 270 Arg Glu
Glu Lys Val Thr Phe Ser His Cys Val Pro Thr Ile Leu Gln 275 280 285
Met Leu Leu Asn Cys Pro Asn Ala Gln Gly Gln Asp Phe Gly Gly Trp 290
295 300 Lys Ile Ile Ile Gly Gly Ser Ser Leu Asn Arg Ser Leu Tyr Gln
Ala 305 310 315 320 Ala Leu Ala Arg Gly Ile Gln Leu Thr Ala Ala Tyr
Gly Met Ser Glu 325 330 335 Thr Cys Pro Leu Ile Ser Ala Ala His Leu
Asn Asp Glu Leu Gln Ala 340 345 350 Gly Ser Glu Asp Glu Arg Val Thr
Tyr Arg Ile Lys Ala Gly Val Pro 355 360 365 Val Pro Leu Val Glu Ala
Ala Ile Val Asp Gly Glu Gly Asn Phe Leu 370 375 380 Pro Ala Asp Gly
Glu Thr Gln Gly Glu Leu Val Leu Arg Ala Pro Trp 385 390 395 400 Leu
Thr Met Gly Tyr Phe Lys Glu Pro Glu Lys Ser Glu Glu Leu Trp 405 410
415 Gln Gly Gly Trp Leu His Thr Gly Asp Val Ala Thr Leu Asp Gly Met
420 425 430 Gly Tyr Ile Asp Ile Arg Asp Arg Ile Lys Asp Val Ile Lys
Thr Gly 435 440 445 Gly Glu Trp Val Ser Ser Leu Asp Leu Glu Asp Leu
Ile Ser Arg His 450 455 460 Pro Ala Val Arg Glu Val Ala Val Val Gly
Val Ala Asp Pro Gln Trp 465 470 475 480 Gly Glu Arg Pro Phe Ala Leu
Leu Val Ala Arg Asp Gly His Asp Ile 485 490 495 Asp Ala Lys Ala Leu
Lys Glu His Leu Lys Pro Phe Val Glu Gln Gly 500 505 510 His Ile Asn
Lys Trp Ala Ile Pro Ser Gln Ile Ala Leu Val Thr Glu 515 520 525 Ile
Pro Lys Thr Ser Val Gly Lys Leu Asp Lys Lys Arg Ile Arg Gln 530 535
540 Asp Ile Val Gln Trp Gln Ala Ser Asn Ser Ala Phe Leu Ser Thr Leu
545 550 555 560 15858DNAPseudomonas aeruginosa 15atgcccaccg
cctggctcga cctgcccgcc ccacccgccc tgcccggcct gttcctgcgc 60gccgcactgc
gccgcggcat ccgcggcaag gccctgcccg agcgcggcct gcgcagccag
120gtcacggtgg acccgaagca cctcgagcgc taccgccagg tctgcggctt
ccgcgacgac 180ggcctgctgc cgccgaccta cccgcacatc ctcgccttcc
cgctgcagat ggcgctgctc 240accgacaagc gcttcccctt cccgctgctc
ggcctggtcc acctggagaa ccgcatcgac 300gtgctgcgcg cgctcggcgg
cctcggcccg ttcaccgtga gcgtcgcggt ggaaaacctg 360caaccgcacg
acaagggcgc caccttcagc atcgtcaccc gcctggaaga ccagcttggc
420ctgctctggg tcggcgacag caaggtgctc tgccgcggcg tcaaggtgcc
cggcgaaatt 480ccgccgaaag ccgagcagga gccgctgccg ctggagccgg
tcgacaactg gaaggcgccc 540gccgacatcg gccggcgcta tgcccgtgcc
gccggcgact acaacccgat ccacctgtcg 600gcgcccagcg ccaagctgtt
cggctttccc cgcgccatcg cccacggcct gtggaacaag 660gctcgcagcc
tggccgccct cggcgagcga ctgccagcct cgggctatcg ggtcgaggtg
720cgcttccaga agccagtgct gctgccggcc agcctcaccc tcctggccag
cgcggcggcg 780gcggacggcc agttcagcct gcgcggcaag gacgacctgc
cgcacatggc cgggcattgg 840agccggctac agggctga 85816285PRTPseudomonas
aeruginosa 16Met Pro Thr Ala Trp Leu Asp Leu Pro Ala Pro Pro Ala
Leu Pro Gly 1 5 10 15 Leu Phe Leu Arg Ala Ala Leu Arg Arg Gly Ile
Arg Gly Lys Ala Leu 20 25 30 Pro Glu Arg Gly Leu Arg Ser Gln Val
Thr Val Asp Pro Lys His Leu 35 40 45 Glu Arg Tyr Arg Gln Val Cys
Gly Phe Arg Asp Asp Gly Leu Leu Pro 50 55 60 Pro Thr Tyr Pro His
Ile Leu Ala Phe Pro Leu Gln Met Ala Leu Leu 65 70 75 80 Thr Asp Lys
Arg Phe Pro Phe Pro Leu Leu Gly Leu Val His Leu Glu 85 90 95 Asn
Arg Ile Asp Val Leu Arg Ala Leu Gly Gly Leu Gly Pro Phe Thr 100 105
110 Val Ser Val Ala Val Glu Asn Leu Gln Pro His Asp Lys Gly Ala Thr
115 120 125 Phe Ser Ile Val Thr Arg Leu Glu Asp Gln Leu Gly Leu Leu
Trp Val 130 135 140 Gly Asp Ser Lys Val Leu Cys Arg Gly Val Lys Val
Pro Gly Glu Ile 145 150 155 160 Pro Pro Lys Ala Glu Gln Glu Pro Leu
Pro Leu Glu Pro Val Asp Asn 165 170 175 Trp Lys Ala Pro Ala Asp Ile
Gly Arg Arg Tyr Ala Arg Ala Ala Gly 180 185 190 Asp Tyr Asn Pro Ile
His Leu Ser Ala Pro Ser Ala Lys Leu Phe Gly 195 200 205 Phe Pro Arg
Ala Ile Ala His Gly Leu Trp Asn Lys Ala Arg Ser Leu 210 215 220 Ala
Ala Leu Gly Glu Arg Leu Pro Ala Ser Gly Tyr Arg Val Glu Val 225 230
235 240 Arg Phe Gln Lys Pro Val Leu Leu Pro Ala Ser Leu Thr Leu Leu
Ala 245 250 255 Ser Ala Ala Ala Ala Asp Gly Gln Phe Ser Leu Arg Gly
Lys Asp Asp 260 265 270 Leu Pro His Met Ala Gly His Trp Ser Arg Leu
Gln Gly 275 280 285 171683DNAPseudomonas aeruginosa 17atgcgagaaa
agcaggaatc gggtagcgtg ccggtgcccg ccgagttcat gagtgcacag 60agcgccatcg
tcggcctgcg cggcaaggac ctgctgacga cggtccgcag cctggctgtc
120cacggcctgc gccagccgct gcacagtgcg cggcacctgg tcgccttcgg
aggccagttg 180ggcaaggtgc tgctgggcga caccctgcac cagccgaacc
cacaggacgc ccgcttccag 240gatccatcct ggcgcctcaa tcccttctac
cggcgcaccc tgcaggccta cctggcgtgg 300cagaaacaac tgctcgcctg
gatcgacgaa agcaacctgg actgcgacga tcgcgcccgc 360gcccgcttcc
tcgtcgcctt gctctccgac gccgtggcac ccagcaacag cctgatcaat
420ccactggcgt taaaggaact gttcaatacc ggcgggatca gcctgctcaa
tggcgtccgc 480cacctgctcg aagacctggt gcacaacggc ggcatgccca
gccaggtgaa caagaccgcc 540ttcgagatcg gtcgcaacct cgccaccacg
caaggcgcgg tggtgttccg caacgaggtg 600ctggagctga tccagtacaa
gccgctgggc gagcgccagt acgccaagcc cctgctgatc 660gtgccgccgc
agatcaacaa gtactacatc ttcgacctgt cgccggaaaa gagcttcgtc
720cagtacgccc tgaagaacaa cctgcaggtc ttcgtcatca gttggcgcaa
ccccgacgcc 780cagcaccgcg aatggggcct gagcacctat gtcgaggccc
tcgaccaggc catcgaggtc 840agccgcgaga tcaccggcag ccgcagcgtg
aacctggccg gcgcctgcgc cggcgggctc 900accgtagccg ccttgctcgg
ccacctgcag gtgcgccggc aactgcgcaa ggtcagtagc 960gtcacctacc
tggtcagcct gctcgacagc cagatggaaa gcccggcgat gctcttcgcc
1020gacgagcaga ccctggagag cagcaagcgc cgctcctacc agcatggcgt
gctggacggg 1080cgcgacatgg ccaaggtgtt cgcctggatg cgccccaacg
acctgatctg gaactactgg 1140gtcaacaact acctgctcgg caggcagccg
ccggcgttcg acatcctcta ctggaacaac 1200gacaacacgc ggctgcccgc
ggcgttccac ggcgaactgc tcgacctgtt caagcacaac 1260ccgctgaccc
gcccgggcgc gctggaggtc agcgggaccg cggtggacct gggcaaggtg
1320gcgatcgaca gcttccacgt cgccggcatc accgaccaca tcacgccctg
ggacgcggtg 1380tatcgctcgg ccctcctgct gggcggccag cgccgcttca
tcctgtccaa cagcgggcac 1440atccagagca tcctcaaccc tcccggaaac
cccaaggcct gctacttcga gaacgacaag 1500ctgagcagcg atccacgcgc
ctggtactac gacgccaagc gcgaagaggg cagctggtgg 1560ccggtctggc
tgggctggct gcaggagcgc tcgggcgagc tgggcaaccc tgacttcaac
1620cttggcagcg ccgcgcatcc gcccctcgaa gcggccccgg gcacctacgt
gcatatacgc 1680tga 168318560PRTPseudomonas aeruginosa 18Met Arg Glu
Lys Gln Glu Ser Gly Ser Val Pro Val Pro Ala Glu Phe 1 5 10 15 Met
Ser Ala Gln Ser Ala Ile Val Gly Leu Arg Gly Lys Asp Leu Leu 20 25
30 Thr Thr Val Arg Ser Leu Ala Val His Gly Leu Arg Gln Pro Leu His
35 40 45 Ser Ala Arg His Leu Val Ala Phe Gly Gly Gln Leu Gly Lys
Val Leu 50 55 60 Leu Gly Asp Thr Leu His Gln Pro Asn Pro Gln Asp
Ala Arg Phe Gln 65 70 75 80 Asp Pro Ser Trp Arg Leu Asn Pro Phe Tyr
Arg Arg Thr Leu Gln Ala 85 90 95 Tyr Leu Ala Trp Gln Lys Gln Leu
Leu Ala Trp Ile Asp Glu Ser Asn 100 105 110 Leu Asp Cys Asp Asp Arg
Ala Arg Ala Arg Phe Leu Val Ala Leu Leu 115 120 125 Ser Asp Ala Val
Ala Pro Ser Asn Ser Leu Ile Asn Pro Leu Ala Leu 130 135 140 Lys Glu
Leu Phe Asn Thr Gly Gly Ile Ser Leu Leu Asn Gly Val Arg 145 150 155
160 His Leu Leu Glu Asp Leu Val His Asn Gly Gly Met Pro Ser Gln Val
165 170 175 Asn Lys Thr Ala Phe Glu Ile Gly Arg Asn Leu Ala Thr Thr
Gln Gly 180 185 190 Ala Val Val Phe Arg Asn Glu Val Leu Glu Leu Ile
Gln Tyr Lys Pro 195 200 205 Leu Gly Glu Arg Gln Tyr Ala Lys Pro Leu
Leu Ile Val Pro Pro Gln 210 215 220 Ile Asn Lys Tyr Tyr Ile Phe Asp
Leu Ser Pro Glu Lys Ser Phe Val 225 230 235 240 Gln Tyr Ala Leu Lys
Asn Asn Leu Gln Val Phe Val Ile Ser Trp Arg 245 250 255 Asn Pro Asp
Ala Gln His Arg Glu Trp Gly Leu Ser Thr Tyr Val Glu 260 265 270 Ala
Leu Asp Gln Ala Ile Glu Val Ser Arg Glu Ile Thr Gly Ser Arg 275 280
285 Ser Val Asn Leu Ala Gly Ala Cys Ala Gly Gly Leu Thr Val Ala Ala
290 295 300 Leu Leu Gly His Leu Gln Val Arg Arg Gln Leu Arg Lys Val
Ser Ser 305 310 315 320 Val Thr Tyr Leu Val Ser Leu Leu Asp Ser Gln
Met Glu Ser Pro Ala 325 330 335 Met Leu Phe Ala Asp Glu Gln Thr Leu
Glu Ser Ser Lys Arg Arg Ser 340 345 350 Tyr Gln His Gly Val Leu Asp
Gly Arg Asp Met Ala Lys Val Phe Ala 355 360 365 Trp Met Arg Pro Asn
Asp Leu Ile Trp Asn Tyr Trp Val Asn Asn Tyr 370 375 380 Leu Leu Gly
Arg Gln Pro Pro Ala Phe Asp Ile Leu Tyr Trp Asn Asn 385 390 395 400
Asp Asn Thr Arg Leu Pro Ala Ala Phe His Gly Glu Leu Leu Asp Leu 405
410 415 Phe Lys His Asn Pro Leu Thr Arg Pro Gly Ala Leu Glu Val Ser
Gly 420 425 430 Thr Ala Val Asp Leu Gly Lys Val Ala Ile Asp Ser Phe
His Val Ala 435 440 445 Gly Ile Thr Asp His Ile Thr Pro Trp Asp Ala
Val Tyr Arg Ser Ala 450 455 460 Leu Leu Leu Gly Gly Gln Arg Arg Phe
Ile Leu Ser Asn Ser Gly His 465 470 475 480 Ile Gln Ser Ile Leu Asn
Pro Pro Gly Asn Pro Lys Ala Cys Tyr Phe 485 490 495 Glu Asn Asp Lys
Leu Ser Ser Asp Pro Arg Ala Trp Tyr Tyr Asp Ala 500 505 510 Lys Arg
Glu Glu Gly Ser Trp Trp Pro Val Trp Leu Gly Trp Leu Gln 515 520 525
Glu Arg Ser Gly Glu Leu Gly Asn Pro Asp Phe Asn Leu Gly Ser Ala 530
535 540 Ala His Pro Pro Leu Glu Ala Ala Pro Gly Thr Tyr Val His Ile
Arg 545 550 555 560 19930DNAUmbellularia californicaCDS(21)..(923)
19cccgggagga ggattataaa atg act cta gag tgg aaa ccg aaa cca aaa ctg
53 Met Thr Leu Glu Trp Lys Pro Lys Pro Lys Leu 1 5 10 cct caa ctg
ctg gat gat cac ttc ggt ctg cac ggt ctg gtg ttt cgt 101Pro Gln Leu
Leu Asp Asp His Phe Gly Leu His Gly Leu Val Phe Arg 15 20 25 cgt
act ttc gca att cgt tct tat gaa gtg ggt cca gat cgt tct acc 149Arg
Thr Phe Ala Ile Arg Ser Tyr Glu Val Gly Pro Asp Arg Ser Thr 30 35
40 tcc atc ctg gcc gtc atg aac cac atg cag gaa gcc acc ctg aat cac
197Ser Ile Leu Ala Val Met Asn His Met Gln Glu Ala Thr Leu Asn His
45 50 55 gcg aaa tct gtt ggt atc ctg ggt gat ggt ttc ggc act act
ctg gaa 245Ala Lys Ser Val Gly Ile Leu Gly Asp Gly Phe Gly Thr Thr
Leu Glu 60 65 70 75 atg tct aaa cgt gac ctg atg tgg gta gtg cgt cgc
acc cac gta gca 293Met Ser Lys Arg Asp Leu Met Trp Val Val Arg Arg
Thr His Val Ala 80 85 90 gta gag cgc tac cct act tgg ggt gac act
gtg gaa gtc gag tgt tgg 341Val Glu Arg Tyr Pro Thr Trp Gly Asp Thr
Val Glu Val Glu Cys Trp 95 100 105 att ggc gcg tcc ggt aac aat ggt
atg cgt cgc gat ttt ctg gtc cgt 389Ile Gly Ala Ser Gly Asn Asn Gly
Met Arg Arg Asp Phe Leu Val Arg 110 115 120 gac tgt aaa acg ggc gaa
atc ctg acg cgt tgc acc tcc ctg agc gtt 437Asp Cys Lys Thr Gly Glu
Ile Leu Thr Arg Cys Thr Ser Leu Ser Val 125 130 135 ctg atg aac acc
cgc act cgt cgc ctg tct acc atc ccg gac gaa gtg 485Leu Met Asn Thr
Arg Thr Arg Arg Leu Ser Thr Ile Pro Asp Glu Val
140 145 150 155 cgc ggt gag atc ggt cct gct ttc atc gat aac gtg gca
gtt aaa gac 533Arg Gly Glu Ile Gly Pro Ala Phe Ile Asp Asn Val Ala
Val Lys Asp 160 165 170 gac gaa atc aag aaa ctg caa aaa ctg aac gac
tcc acc gcg gac tac 581Asp Glu Ile Lys Lys Leu Gln Lys Leu Asn Asp
Ser Thr Ala Asp Tyr 175 180 185 atc cag ggc ggt ctg act ccg cgc tgg
aac gac ctg gat gtt aat cag 629Ile Gln Gly Gly Leu Thr Pro Arg Trp
Asn Asp Leu Asp Val Asn Gln 190 195 200 cat gtg aac aac ctg aaa tac
gtt gct tgg gtc ttc gag act gtg ccg 677His Val Asn Asn Leu Lys Tyr
Val Ala Trp Val Phe Glu Thr Val Pro 205 210 215 gac agc att ttc gaa
agc cat cac att tcc tct ttt act ctg gag tac 725Asp Ser Ile Phe Glu
Ser His His Ile Ser Ser Phe Thr Leu Glu Tyr 220 225 230 235 cgt cgc
gaa tgt act cgc gac tcc gtt ctg cgc agc ctg acc acc gta 773Arg Arg
Glu Cys Thr Arg Asp Ser Val Leu Arg Ser Leu Thr Thr Val 240 245 250
agc ggc ggt tct agc gag gca ggt ctg gtc tgc gac cat ctg ctg caa
821Ser Gly Gly Ser Ser Glu Ala Gly Leu Val Cys Asp His Leu Leu Gln
255 260 265 ctg gaa ggc ggc tcc gaa gtc ctg cgt gcg cgt acg gag tgg
cgt cca 869Leu Glu Gly Gly Ser Glu Val Leu Arg Ala Arg Thr Glu Trp
Arg Pro 270 275 280 aag ctg acg gat tct ttc cgc ggc atc tcc gta att
ccg gcg gaa cct 917Lys Leu Thr Asp Ser Phe Arg Gly Ile Ser Val Ile
Pro Ala Glu Pro 285 290 295 cgt gtt taagctt 930Arg Val 300
20301PRTUmbellularia californica 20Met Thr Leu Glu Trp Lys Pro Lys
Pro Lys Leu Pro Gln Leu Leu Asp 1 5 10 15 Asp His Phe Gly Leu His
Gly Leu Val Phe Arg Arg Thr Phe Ala Ile 20 25 30 Arg Ser Tyr Glu
Val Gly Pro Asp Arg Ser Thr Ser Ile Leu Ala Val 35 40 45 Met Asn
His Met Gln Glu Ala Thr Leu Asn His Ala Lys Ser Val Gly 50 55 60
Ile Leu Gly Asp Gly Phe Gly Thr Thr Leu Glu Met Ser Lys Arg Asp 65
70 75 80 Leu Met Trp Val Val Arg Arg Thr His Val Ala Val Glu Arg
Tyr Pro 85 90 95 Thr Trp Gly Asp Thr Val Glu Val Glu Cys Trp Ile
Gly Ala Ser Gly 100 105 110 Asn Asn Gly Met Arg Arg Asp Phe Leu Val
Arg Asp Cys Lys Thr Gly 115 120 125 Glu Ile Leu Thr Arg Cys Thr Ser
Leu Ser Val Leu Met Asn Thr Arg 130 135 140 Thr Arg Arg Leu Ser Thr
Ile Pro Asp Glu Val Arg Gly Glu Ile Gly 145 150 155 160 Pro Ala Phe
Ile Asp Asn Val Ala Val Lys Asp Asp Glu Ile Lys Lys 165 170 175 Leu
Gln Lys Leu Asn Asp Ser Thr Ala Asp Tyr Ile Gln Gly Gly Leu 180 185
190 Thr Pro Arg Trp Asn Asp Leu Asp Val Asn Gln His Val Asn Asn Leu
195 200 205 Lys Tyr Val Ala Trp Val Phe Glu Thr Val Pro Asp Ser Ile
Phe Glu 210 215 220 Ser His His Ile Ser Ser Phe Thr Leu Glu Tyr Arg
Arg Glu Cys Thr 225 230 235 240 Arg Asp Ser Val Leu Arg Ser Leu Thr
Thr Val Ser Gly Gly Ser Ser 245 250 255 Glu Ala Gly Leu Val Cys Asp
His Leu Leu Gln Leu Glu Gly Gly Ser 260 265 270 Glu Val Leu Arg Ala
Arg Thr Glu Trp Arg Pro Lys Leu Thr Asp Ser 275 280 285 Phe Arg Gly
Ile Ser Val Ile Pro Ala Glu Pro Arg Val 290 295 300
21420DNAPseudomonas putida 21atggccaaag tgattgcgaa gaaaaaagac
gaagccctgg acacgcttgg cgaggtgcgc 60ggctatgcgc gcaagatctg gctggccggt
atcggcgcct acgcccgcgt cggtcaggaa 120ggcgctgact acttcaaaga
gctggtcagg gcgggtgaag gtgtcgagaa gcgcggcaag 180aagcgcatcg
acaaagagct cgatgcggcc aaccaccagc ttgacgaagt cggtgaagaa
240gtgagccgcg tacgcggcaa ggtagaaatt caactcgaca agatcgaaaa
agctttcgac 300gcacgggtcg gtcgcgcctt gaatcgcctg ggtattccgt
ctaaacatga cgttgaggcg 360ttgtcgatca agcttgaaca gttgcatgag
ctgcttgagc gcgtcgcgca caaaccataa 42022139PRTPseudomonas putida
22Met Ala Lys Val Ile Ala Lys Lys Lys Asp Glu Ala Leu Asp Thr Leu 1
5 10 15 Gly Glu Val Arg Gly Tyr Ala Arg Lys Ile Trp Leu Ala Gly Ile
Gly 20 25 30 Ala Tyr Ala Arg Val Gly Gln Glu Gly Ala Asp Tyr Phe
Lys Glu Leu 35 40 45 Val Arg Ala Gly Glu Gly Val Glu Lys Arg Gly
Lys Lys Arg Ile Asp 50 55 60 Lys Glu Leu Asp Ala Ala Asn His Gln
Leu Asp Glu Val Gly Glu Glu 65 70 75 80 Val Ser Arg Val Arg Gly Lys
Val Glu Ile Gln Leu Asp Lys Ile Glu 85 90 95 Lys Ala Phe Asp Ala
Arg Val Gly Arg Ala Leu Asn Arg Leu Gly Ile 100 105 110 Pro Ser Lys
His Asp Val Glu Ala Leu Ser Ile Lys Leu Glu Gln Leu 115 120 125 His
Glu Leu Leu Glu Arg Val Ala His Lys Pro 130 135 23786DNAPseudomonas
putida 23atggctggca agaagaacac cgaaaaagaa ggcagctcct gggtcggcgg
gatcgagaaa 60tactcccgca agatctggct ggcggggctg ggtatctatt cgaagatcga
ccaggacggc 120ccgaagctgt tcgactcgct ggtgaaggat ggcgagaagg
ccgagaagca ggcgaaaaag 180acggctgaag atgttgccga gactgccaag
tcttcgacca cttcgcgggt gtcgggcgtg 240aaggaccgtg cgctgggcaa
gtggagcgaa cttgaagaag ccttcgacaa gcgccttaac 300agcgccatct
cgcgccttgg cgtgccgagc cgcaacgaga tcaaggcact gcaccagcag
360gtggacagcc tgaccaagca gatcgagaag ctgaccggtg cttcggttac
gccgatttcg 420tcgcgcgctg cagcaaccaa gccggctgca agcaaggctg
cggccaagcc actggccaag 480gcagcagcta agcctgcggc gaaaacggcg
gcggccaaac ctgctggcaa aaccgcagcg 540gccaaacccg cagccaaaac
cgcagcggaa aaacctgcag ctaagccagc agccaagcct 600gcagcggcca
aacctgcggc agccaagaaa cctgcggtga agaaagctcc agccaaaccg
660gcagcggcca aaccagcagc accagctgcc agcgctgcgc ctgcagcgac
cacagcaccg 720gcaactgccg ccaccccggc cagcagcacg ccgtcggcac
cgactggcac cggtaccctg 780atctga 78624261PRTPseudomonas putida 24Met
Ala Gly Lys Lys Asn Thr Glu Lys Glu Gly Ser Ser Trp Val Gly 1 5 10
15 Gly Ile Glu Lys Tyr Ser Arg Lys Ile Trp Leu Ala Gly Leu Gly Ile
20 25 30 Tyr Ser Lys Ile Asp Gln Asp Gly Pro Lys Leu Phe Asp Ser
Leu Val 35 40 45 Lys Asp Gly Glu Lys Ala Glu Lys Gln Ala Lys Lys
Thr Ala Glu Asp 50 55 60 Val Ala Glu Thr Ala Lys Ser Ser Thr Thr
Ser Arg Val Ser Gly Val 65 70 75 80 Lys Asp Arg Ala Leu Gly Lys Trp
Ser Glu Leu Glu Glu Ala Phe Asp 85 90 95 Lys Arg Leu Asn Ser Ala
Ile Ser Arg Leu Gly Val Pro Ser Arg Asn 100 105 110 Glu Ile Lys Ala
Leu His Gln Gln Val Asp Ser Leu Thr Lys Gln Ile 115 120 125 Glu Lys
Leu Thr Gly Ala Ser Val Thr Pro Ile Ser Ser Arg Ala Ala 130 135 140
Ala Thr Lys Pro Ala Ala Ser Lys Ala Ala Ala Lys Pro Leu Ala Lys 145
150 155 160 Ala Ala Ala Lys Pro Ala Ala Lys Thr Ala Ala Ala Lys Pro
Ala Gly 165 170 175 Lys Thr Ala Ala Ala Lys Pro Ala Ala Lys Thr Ala
Ala Glu Lys Pro 180 185 190 Ala Ala Lys Pro Ala Ala Lys Pro Ala Ala
Ala Lys Pro Ala Ala Ala 195 200 205 Lys Lys Pro Ala Val Lys Lys Ala
Pro Ala Lys Pro Ala Ala Ala Lys 210 215 220 Pro Ala Ala Pro Ala Ala
Ser Ala Ala Pro Ala Ala Thr Thr Ala Pro 225 230 235 240 Ala Thr Ala
Ala Thr Pro Ala Ser Ser Thr Pro Ser Ala Pro Thr Gly 245 250 255 Thr
Gly Thr Leu Ile 260 2548DNAArtificial SequencePrimer 25gacgatgaat
tcaggaggta ttaataatga gccaggtcca gaacattc 482630DNAArtificial
SequencePrimer 26gacgatggat ccggcccgac ggtagggaaa
302748DNAArtificial SequencePrimer 27gacgatgaat tcaggaggta
ttaataatgg cgctcgatcc tgaggtgc 482833DNAArtificial SequencePrimer
28gacgatggat cccttcgctt cagtccggcc gct 332947DNAArtificial
SequencePrimer 29gacgatgaat tcaggaggta ttaataatgc ccaccgcctg
gctcgac 473033DNAArtificial SequencePrimer 30gacgaaggat cctcagccct
gtagccggct cca 333148DNAArtificial SequencePrimer 31gacgatgaat
tcaggaggta ttaataatgc cattcgtacc cgtagcag 483233DNAArtificial
SequencePrimer 32gacgatggat cctcagacga agcagaggct gag
333347DNAArtificial SequencePrimer 33ggggagctca ggaggtataa
ttaatgagtc agaagaacaa taacgag 473430DNAArtificial SequencePrimer
34gggggtacct catcgttcat gcacgtaggt 303546DNAArtificial
SequencePrimer 35ggggagctca ggaggtataa ttaatgcgag aaaagcagga atcggg
463632DNAArtificial SequencePrimer 36gggggtacct cagcgtatat
gcacgtaggt gc 323746DNAArtificial SequencePrimer 37gggtctagaa
ggaggtataa ttaatgcgag aaaagcagga atcggg 463832DNAArtificial
SequencePrimer 38gggaagcttt cagcgtatat gcacgtaggt gc
323944DNAArtificial SequencePrimer 39gggggtacca ggaggtataa
ttaatgttgc agacacgcat catc 444030DNAArtificial SequencePrimer
40gggtctagat tacaacgtgg aaaggaacgc 304160DNAArtificial
SequencePrimer 41ggtcagacca ctttatttat ttttttacag gggagtgtta
gcggcatgcg ttcctattcc 604260DNAArtificial SequencePrimer
42ctccgccatt cagcgcggat tcatatagct ttgaccttct taaacacgag gttccgccgg
604360DNAArtificial SequencePrimer 43gagtccaact ttgttttgct
gtgttatgga aatctcacta gcggcatgcg ttcctattcc 604460DNAArtificial
SequencePrimer 44acccctcgtt tgaggggttt gctctttaaa cggaagggat
taaacacgag gttccgccgg 604532DNAArtificial SequencePrimer
45gggctcgagt taaccggcac ggaactcgct cg 324636DNAArtificial
SequencePrimer 46gggctcgagt tggtaacgaa tcagacaatt gacggc
364770DNAArtificial SequencePrimer 47tgaataattg cttgttttta
aagaaaaaga aacagcggct ggtccgctgt gtgtaggctg 60gagctgcttc
704841DNAArtificial SequencePrimer 48tcgatggtgt caacgtaaat
gattccgggg atccgtcgac c 414921DNAArtificial SequencePrimer
49catttacgtt gacaccatcg a 215022DNAArtificial SequencePrimer
50tcaggcttta ttgtccactt tg 225163DNAArtificial SequencePrimer
51caggtcagac cactttattt atttttttac aggggagtgt gaagcggcat gcgttcctat
60tcc 635260DNAArtificial SequencePrimer 52ttgcaggtca gttgcagttg
ttttccaaaa actttcccca gtgtaggctg gagctgcttc 605363DNAArtificial
SequencePrimer 53tctggtacga ccagatcacc ttgcggattc aggagactga
gaagcggcat gcgttcctat 60tcc 635460DNAArtificial SequencePrimer
54aacccgctca aacaccgtcg caataccctg acccagaccg gtgtaggctg gagctgcttc
60
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References