U.S. patent application number 14/886437 was filed with the patent office on 2016-02-04 for production of alkenes by combined enzymatic conversion of 3-hydroxyalkanoic acids.
This patent application is currently assigned to Global Bioenergies. The applicant listed for this patent is Global Bioenergies, Scientist of Fortune, S.A.. Invention is credited to Maria Anissimova, Marc Delcourt, Philippe Marliere, Richard Tallon.
Application Number | 20160032326 14/886437 |
Document ID | / |
Family ID | 43734239 |
Filed Date | 2016-02-04 |
United States Patent
Application |
20160032326 |
Kind Code |
A1 |
Marliere; Philippe ; et
al. |
February 4, 2016 |
Production of Alkenes by Combined Enzymatic Conversion of
3-Hydroxyalkanoic Acids
Abstract
The present invention relates to a method for generating alkenes
through a biological process. More specifically, the invention
relates to a method for producing alkenes (for example propylene,
ethylene, 1-butylene, isobutylene or isoamylene) from molecules of
the 3-hydroxyalkanoate type.
Inventors: |
Marliere; Philippe;
(Mouscron, BE) ; Delcourt; Marc; (Paris, FR)
; Anissimova; Maria; (Nozay, FR) ; Tallon;
Richard; (Orsay, FR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Global Bioenergies
Scientist of Fortune, S.A. |
Evry Cedex |
|
FR |
|
|
Assignee: |
Global Bioenergies
Scientist of Fortune, S.A.
|
Family ID: |
43734239 |
Appl. No.: |
14/886437 |
Filed: |
October 19, 2015 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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13880042 |
Jul 6, 2013 |
9193978 |
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PCT/EP2011/068174 |
Oct 18, 2011 |
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14886437 |
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Current U.S.
Class: |
435/167 ;
435/252.3; 435/252.31; 435/252.33; 435/254.11; 435/254.2;
435/254.21; 435/254.3; 435/254.6; 435/257.2; 435/325; 435/419 |
Current CPC
Class: |
C12N 9/88 20130101; C12P
5/026 20130101; C12Y 401/01033 20130101; C12P 5/02 20130101 |
International
Class: |
C12P 5/02 20060101
C12P005/02; C12N 9/88 20060101 C12N009/88 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 19, 2010 |
EP |
10188001 |
Claims
1-19. (canceled)
20. A method for producing an alkene comprising the conversion of a
3-hydroxyalkanoate into said alkene by: (i) a first enzyme having
an activity of converting the 3-hydroxyalkanoate into the
corresponding 3-phosphonoxyalkanoate; and (ii) a second enzyme
being different from the first enzyme and having an activity of
converting said 3-phosphonoxyalkanoate into said alkene.
21. The method of claim 20, wherein the first enzyme is a
mevalonate diphosphate (MDP) decarboxylase and the second enzyme is
a different mevalonate diphosphate (MDP) decarboxylase.
22. The method of claim 20 wherein: (i) the first enzyme is
selected from the group consisting of: (A) a protein comprising the
amino acid sequence as shown in SEQ ID NO: 1 or a protein
comprising an amino acid sequence which is at least 75% identical
to the amino acid sequence shown in SEQ ID NO: 1 and showing an
activity of converting the 3-hydroxyalkanoate into the
corresponding 3-phosphonoxyalkanoate which is at least as high as
the corresponding activity of the protein having the amino acid
sequence shown in SEQ ID NO: 1; (B) a protein comprising the amino
acid sequence as shown in SEQ ID NO: 2 or a protein comprising an
amino acid sequence which is at least 75% identical to the amino
acid sequence shown in SEQ ID NO: 2 and showing an activity of
converting the 3-hydroxyalkanoate into the corresponding
3-phosphonoxyalkanoate which is at least as high as the
corresponding activity of the protein having the amino acid
sequence shown in SEQ ID NO: 2; (C) a protein comprising the amino
acid sequence as shown in SEQ ID NO: 3 or a protein comprising an
amino acid sequence which is at least 75% identical to the amino
acid sequence shown in SEQ ID NO: 3 and showing an activity of
converting the 3-hydroxyalkanoate into the corresponding
3-phosphonoxyalkanoate which is at least as high as the
corresponding activity of the protein having the amino acid
sequence shown in SEQ ID NO: 3; and (D) a protein comprising the
amino acid sequence as shown in SEQ ID NO: 4 or a protein
comprising an amino acid sequence which is at least 75% identical
to the amino acid sequence shown in SEQ ID NO: 4 and showing an
activity of converting the 3-hydroxyalkanoate into the
corresponding 3-phosphonoxyalkanoate which is at least as high as
the corresponding activity of the protein having the amino acid
sequence shown in SEQ ID NO: 4; and (ii) the second enzyme is
selected from the group consisting of: (a) a protein comprising the
amino acid sequence as shown in SEQ ID NO: 5 or a protein
comprising an amino acid sequence which is at least 75% identical
to the amino acid sequence shown in SEQ ID NO: 5 and showing an
activity of converting said 3-phosphonoxyalkanoate into said alkene
which is at least as high as the corresponding activity of the
protein having the amino acid sequence shown in SEQ ID NO: 5; (b) a
protein comprising the amino acid sequence as shown in SEQ ID NO: 6
or a protein comprising an amino acid sequence which is at least
75% identical to the amino acid sequence shown in SEQ ID NO: 6 and
showing an activity of converting said 3-phosphonoxyalkanoate into
said alkene which is at least as high as the corresponding activity
of the protein having the amino acid sequence shown in SEQ ID NO:
6; (c) a protein comprising the amino acid sequence as shown in SEQ
ID NO: 7 or a protein comprising an amino acid sequence which is at
least 75% identical to the amino acid sequence shown in SEQ ID NO:
7 and showing an activity of converting said 3-phosphonoxyalkanoate
into said alkene which is at least as high as the corresponding
activity of the protein having the amino acid sequence shown in SEQ
ID NO: 7; (d) a protein comprising the amino acid sequence as shown
in SEQ ID NO: 8 or a protein comprising an amino acid sequence
which is at least 75% identical to the amino acid sequence shown in
SEQ ID NO: 8 and showing an activity of converting said
3-phosphonoxyalkanoate into said alkene which is at least as high
as the corresponding activity of the protein having the amino acid
sequence shown in SEQ ID NO: 8; (e) a protein comprising the amino
acid sequence as shown in SEQ ID NO: 9 or a protein comprising an
amino acid sequence which is at least 75% identical to the amino
acid sequence shown in SEQ ID NO: 9 and showing an activity of
converting said 3-phosphonoxyalkanoate into said alkene which is at
least as high as the corresponding activity of the protein having
the amino acid sequence shown in SEQ ID NO: 9 (f) a protein
comprising the amino acid sequence as shown in SEQ ID NO: 10 or a
protein comprising an amino acid sequence which is at least 75%
identical to the amino acid sequence shown in SEQ ID NO: 10 and
showing an activity of converting said 3-phosphonoxyalkanoate into
said alkene which is at least as high as the corresponding activity
of the protein having the amino acid sequence shown in SEQ ID NO:
10; (g) a protein comprising the amino acid sequence as shown in
SEQ ID NO: 11 or a protein comprising an amino acid sequence which
is at least 75% identical to the amino acid sequence shown in SEQ
ID NO: 11 and showing an activity of converting said
3-phosphonoxyalkanoate into said alkene which is at least as high
as the corresponding activity of the protein having the amino acid
sequence shown in SEQ ID NO: 11; (h) a protein comprising the amino
acid sequence as shown in SEQ ID NO: 12 or a protein comprising an
amino acid sequence which is at least 75% identical to the amino
acid sequence shown in SEQ ID NO: 12 and showing an activity of
converting said 3-phosphonoxyalkanoate into said alkene which is at
least as high as the corresponding activity of the protein having
the amino acid sequence shown in SEQ ID NO: 12; (i) a protein
comprising the amino acid sequence as shown in SEQ ID NO: 13 or a
protein comprising an amino acid sequence which is at least 75%
identical to the amino acid sequence shown in SEQ ID NO: 13 and
showing an activity of converting said 3-phosphonoxyalkanoate into
said alkene which is at least as high as the corresponding activity
of the protein having the amino acid sequence shown in SEQ ID NO:
13; (j) a protein comprising the amino acid sequence as shown in
SEQ ID NO: 14 or a protein comprising an amino acid sequence which
is at least 75% identical to the amino acid sequence shown in SEQ
ID NO: 14 and showing an activity of converting said
3-phosphonoxyalkanoate into said alkene which is at least as high
as the corresponding activity of the protein having the amino acid
sequence shown in SEQ ID NO: 14; and (k) a protein comprising the
amino acid sequence as shown in SEQ ID NO: 15 or a protein
comprising an amino acid sequence which is at least 75% identical
to the amino acid sequence shown in SEQ ID NO: 15 and showing an
activity of converting said 3-phosphonoxyalkanoate into said alkene
which is at least as high as the corresponding activity of the
protein having the amino acid sequence shown in SEQ ID NO: 15.
23. The method of claim 22, wherein: (a) the first enzyme is a
protein comprising the amino acid sequence as shown in SEQ ID NO: 2
or a protein comprising an amino acid sequence which is at least
75% identical to the amino acid sequence shown in SEQ ID NO: 2 and
showing an activity of converting the 3-hydroxyalkanoate into the
corresponding 3-phosphonoxyalkanoate which is at least as high as
the corresponding activity of the protein having the amino acid
sequence shown in SEQ ID NO: 2; and (b) the second enzyme is a
protein comprising the amino acid sequence as shown in SEQ ID NO:
10 or a protein comprising an amino acid sequence which is at least
75% identical to the amino acid sequence shown in SEQ ID NO: 10 and
showing an activity of converting said 3-phosphonoxyalkanoate into
said alkene which is at least as high as the corresponding activity
of the protein having the amino acid sequence shown in SEQ ID NO:
10.
24. The method of claim 20, wherein the 3-hydroxyalkanoate is
3-hydroxypropionate and the alkene is ethylene.
25. The method of claim 20, wherein the 3-hydroxyalkanoate is
3-hydroxybutyrate and the alkene is propylene.
26. The method of claim 20, wherein the 3-hydroxyalkanoate is
3-hydroxyvalerate and the alkene is 1-butylene.
27. The method of claim 20, wherein the hydroxyalkanoate is
3-hydroxy-3-methylbutyrate and the alkene is isobutylene.
28. The method of claim 20, wherein the 3-hydroxyalkanoate is
3-hydroxy-3-methylvalerate and the alkene is isoamylene.
29. The method of claim 20, characterized in that the conversion
step is carried out in vitro, in a cell-free system.
30. The method of claim 20 characterized in that the method is
carried out in the presence of a microorganism producing said
enzymes as defined in (i) and (ii) of claim 20.
31. The method of claim 20, characterized by the use of a
multicellular organism producing said enzymes as defined in (i) and
(ii) of claim 20.
32. The method of claim 20, comprising a step of collecting gaseous
alkenes degassing out of the reaction.
33. A multicellular organism or a microorganism which produces at
least two enzymes, wherein one enzyme is selected from (i) and the
other enzyme is selected from (ii), wherein (i) and (ii) are as
follows: (i) a first enzyme having an activity of converting the
3-hydroxyalkanoate into the corresponding 3-phosphonoxyalkanoate;
and (ii) a second enzyme being different from the first enzyme and
having an activity of converting said 3-phosphonoxyalkanoate into
said alkene.
34. A method of using the multicellular organism or microorganism
of claim 33 to produce alkenes, comprising the steps of: (i)
culturing the multicellular organism or microorganism of claim 33
with 3-hydroxyalkanoate for a sufficient period of time to allow
for the conversion of a 3-hydroxyalkanoate to an alkene; and (ii)
recovering said alkene.
35. A composition comprising the microorganism of claim 33, a
suitable culture medium and a 3-hydroxyalkanoate compound or a
carbon source that can be converted by the microorganism to a
3-hydroxyalkanoate compound.
36. A method of using a combination of at least two enzymes to
convert a 3-hydroxyalkanoate to an alkene, wherein the method
comprises: (i) contacting a 3-hydroxyalkanoate with: (a) a first
enzyme having an activity of converting the 3-hydroxyalkanoate into
the corresponding 3-phosphonoxyalkanoate; and (b) a second enzyme
being different from the first enzyme and having an activity of
converting said 3-phosphonoxyalkanoate into said alkene; (ii)
converting said 3-hydroxyalkanoate to an alkene.
37. A method for producing an alkene comprising the step of
enzymatically converting a 3-phosphonoxyalkanoate into the
corresponding alkene by use of an enzyme which can catalyze the
conversion via decarboxylation and dephosphorylation.
38. The method of claim 20, wherein the method is carried out with
ATP, dATP, ADP, AMP, an NTP other than ATP, a dNTP or pyrophosphate
as co-substrate.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of Ser. No. 13/880,042,
filed on Jul. 6, 2013, which is the National Phase under 35 U.S.C.
.sctn.371 of PCT International Application No. PCT/EP2011/068174
which has an international filing date of Oct. 18, 2011, which
claims priority to European Patent Application EP10188001 filed on
Oct. 19, 2010. The entire contents of these applications listed
above are hereby incorporated by reference in their entirety.
[0002] The present invention relates to a method for generating
alkenes through a biological process. More specifically, the
invention relates to a method for producing alkenes (for example
propylene, ethylene, 1-butylene, isobutylene or isoamylene) from
molecules of the 3-hydroxyalkanoate type.
[0003] A large number of chemical compounds are currently derived
from petrochemicals. Alkenes (such as ethylene, propylene, the
different butenes, or else the pentenes, for example) are used in
the plastics industry, for example for producing polypropylene or
polyethylene, and in other areas of the chemical industry and that
of fuels.
[0004] Ethylene, the simplest alkene, lies at the heart of
industrial organic chemistry: it is the most widely produced
organic compound in the world. It is used in particular to produce
polyethylene, a major plastic. Ethylene can also be converted to
many industrially useful products by reaction (of oxidation, of
halogenation).
Propylene holds a similarly important role: its polymerization
results in a plastic material, polypropylene. The technical
properties of this product in terms of resistance, density,
solidity, deformability, and transparency are unequalled. The
worldwide production of polypropylene has grown continuously since
its invention in 1954.
[0005] Butylene exists in four forms, one of which, isobutylene,
enters into the composition of methyl-tert-butyl-ether (MTBE), an
anti-knock additive for automobile fuel. Isobutylene can also be
used to produce isooctene, which in turn can be reduced to
isooctane (2,2,4-trimethylpentane); the very high octane rating of
isooctane makes it the best fuel for so-called "gasoline"
engines.
[0006] Amylene, hexene and heptene exist in many forms according to
the position and configuration of the double bond. These products
have real industrial applications but are less important than
ethylene, propylene or butenes.
[0007] All these alkenes are currently produced by catalytic
cracking of petroleum products (or by a derivative of the
Fisher-Tropsch process in the case of hexene, from coal or gas).
Their cost is therefore naturally indexed to the price of oil.
Moreover, catalytic cracking is sometimes associated with
considerable technical difficulties which increase process
complexity and production costs.
[0008] Independently of the above considerations, the bioproduction
of plastics ("bioplastics") is a thriving field. This boom is
driven by economic concerns linked to the price of oil, and by
environmental considerations that are both global (carbon-neutral
products) and local (waste management).
[0009] The main family of bioplastics is that of the
polyhydroxyalkanoates (PHA). These are polymers obtained by
condensation of molecules comprising both an acid group and an
alcohol group. Condensation takes place by esterification of the
acid on the alcohol of the following monomer. This ester bond is
not as stable as the direct carbon-carbon bond present in the
polymers of conventional plastics, which explains why PHAs have a
biodegradability of a few weeks to a few months.
[0010] The PHA family includes in particular poly-3-hydroxybutyrate
(PHB), a polymer of 3-hydroxybutyrate, and
polyhydroxybutyrate-valerate (PHBV), an alternating polymer of
3-hydroxybutyrate and 3-hydroxyvalerate.
[0011] PHB is naturally produced by some strains of bacteria such
as Alcaligenes eutrophus and Bacillus megaterium. Laboratory
bacteria, like E. coli, having integrated synthetic pathways
leading to PHB or to PHAs in general, have been constructed. The
compound or its polymer can, in certain laboratory conditions,
account for up to 80% of the bacterial mass (Wong M S et al.,
Biotech. Bioeng. 99 (2008), 919-928). Industrial-scale production
of PHB was attempted in the 1980s, but the costs of producing the
compound by fermentation were considered too high at the time.
Projects involving the direct production of these compounds in
genetically modified plants (having integrated the key enzymes of
the PHB synthetic pathway present in producer bacteria) are in
progress and might entail lower operating costs.
[0012] The biological production of alkanes or other hydrocarbon
molecules that can be used as fuels or as precursors of synthetic
resins is called for in the context of a sustainable industrial
operation in harmony with geochemical cycles. The first generation
of biofuels consisted in the fermentative production of ethanol, as
fermentation and distillation processes already existed in the food
processing industry. The production of second generation biofuels
is in an exploratory phase, encompassing in particular the
production of long chain alcohols (butanol and pentanol), terpenes,
linear alkanes and fatty acids. Two recent reviews provide a
general overview of research in this field: Ladygina N et al.,
Process Biochemistry, 2006, 41:1001; and Wackett L P, Current
Opinions in Chemical Biology, 2008, 21:187.
[0013] In the alkene chemical family, isoprene
(2-methyl-1,3-butadiene) is the terpene motif which, through
polymerization, leads to rubber. Other terpenes might be developed,
by chemical, biological or mixed pathways, as usable products such
as biofuels or to manufacture plastics. The recent literature shows
that the mevalonate pathway (a key intermediate in steroid
biosynthesis in many organisms) might be used in order to
efficiently produce products from the terpene family at industrial
yields (Withers S T et al., Appl. Environ. Microbiol., 2007,
73:6277).
[0014] The production of alkenes, in particular terminal alkenes,
[ethylene mono- or di-substituted at position 2:
H.sub.2C.dbd.C(R.sup.1)(R.sup.2)] has apparently been less
extensively investigated. The conversion of isovalerate to
isobutylene by the yeast Rhodotorula minuta has been described
(Fujii T. et al., Appl. Environ. Microbiol., 1988, 54:583), but the
efficiency of this reaction, characterized by a very low value of
the turnover number (k.sub.cat is 1.times.10.sup.-5 sec.sup.-1), is
far from permitting an industrial application. The reaction
mechanism was elucidated by Fukuda H et al. (BBRC, 1994,
201(2):516) and involves a cytochrome P450 enzyme which
decarboxylates isovalerate by reduction of an oxoferryl group
Fe.sup.v.dbd.O. At no point does the reaction involve hydroxylation
of isovalerate. Isovalerate is also an intermediate in leucine
catabolism. Large-scale biosynthesis of isobutylene by this pathway
seems highly unfavorable, since it would require the synthesis and
degradation of one molecule of leucine to form one molecule of
isobutylene. Also, the enzyme catalyzing the reaction uses heme as
cofactor, poorly lending itself to recombinant expression in
bacteria and to improvement of enzyme parameters. For all these
reasons, it appears very unlikely that this pathway of the prior
art can serve as a basis for industrial exploitation. Other
microorganisms have been described as being marginally capable of
naturally producing isobutylene from isovalerate; the yields
obtained are even lower than those obtained with Rhodotorula minuta
(Fukuda H. et al, Agric. Biol. Chem., 1984, 48:1679).
[0015] The same studies have also described the natural production
of propylene: many microorganisms are capable of producing
propylene, once again with an extremely low yield. The production
of ethylene by plants has long been known (Meigh et al, 1960,
Nature, 186:902). According to the metabolic pathway elucidated,
methionine is the precursor of ethylene (Adams and Yang, PNAS,
1979, 76:170). Conversion of 2-oxoglutarate has also been described
(Ladygina N et al., Process Biochemistry 2006, 41:1001). Since the
production of a two-carbon molecule of ethylene consumes a four- or
five-carbon molecule precursor, these pathways appear materially
and energetically unfavorable for their industrial application.
[0016] Thus, there is a need for efficient methods for producing
alkenes such as ethylene, propylene, 1-butylene, isobutylene,
1-amylene or isoamylene.
[0017] WO2010/001078 describes a process for producing alkenes by
enzymatic conversion of 3-hydroxyalkanoic acids with an enzyme
having the activity of a decarboxylase. Such a method is
advantageous because it helps to avoid the use of petroleum
products, to lower the costs of producing plastics and fuels and
can have a considerable global environmental impact by allowing
carbon to be stored in solid form. Although the method described in
WO 2010/001078 allows to produce alkenes by enzymatically
converting 3-hydroxyalkanoates, there is still a need for
improvements, in particular as regards efficiency of the process so
as to make it suitable for industrial purposes. The present
application addresses this need.
[0018] The present invention describes a method for producing
alkene compounds starting from a 3-hydroxyalkanoate through a
biological process, in particular an enzymatic process, in which
two types of enzymes are combined in order to increase the
efficiency of the production rate. More specifically, the present
invention relates to a method for producing an alkene,
characterized in that it comprises the conversion of a
3-hydroxyalkanoate into said alkene by [0019] (i) a first enzyme
having an activity of converting the 3-hydroxyalkanoate into the
corresponding 3-phosphonoxyalkanoate; and [0020] (ii) a second
enzyme being different from the first enzyme and having an activity
of converting said 3-phosphonoxyalkanoate into said alkene.
[0021] The present invention also relates to the use of at least
two enzymes, wherein one enzyme is selected from (i) as specified
above and the other enzyme is selected from (ii) as specified above
or of a microorganism producing said combination of enzymes, for
producing an alkene compound from a 3-hydroxyalkanoate.
[0022] The present invention also relates to organisms, preferably
microorganisms, which produce at least two enzymes, wherein one
enzyme is selected from (i) as specified above and the other enzyme
is selected from (ii) as specified above.
[0023] "3-hydroxyalkanoate", as used herein, denotes a molecule
responding to the following general formula:
C.sub.n+1H.sub.2n+2O.sub.3,
with 1<n<7, and comprising 3-hydroxypropionate as a common
motif (FIG. 1), and optionally one or two alkyl substitutions on
carbon 3. Said alkyl residues or groups can be linear or branched.
As used herein, the terms "alkoyl" and "alkyl" have the same
meaning and are interchangeable. Likewise, the terms "residue" and
"group" have the same meaning and are interchangeable. Methyl,
ethyl, propyl, isopropyl, butyl, isobutyl groups are examples of
said alkyl groups. Carbon 3 becomes a chiral center if the two
alkyl substitutions are different. The present definition
encompasses the two chiral forms, even if one of the two forms, for
example the R form, is the main form produced naturally. Examples
of 3-hydroxyalkanoates are presented in FIG. 3. Optionally, alkyl
substituents can be added on carbon 2, which then may also become
chiral (if the two substituents are different). Equally, the
configurations of the 3-hydroxyalkanoate substrates in the present
invention encompass all the stereoisomers. In a preferred
embodiment, the 3-hydroxyalkanoates correspond either to
3-hydroxypropionate or to variants or derivatives of
3-hydroxypropionate in which one of the two or the two hydrogen
atoms carried on carbon 3 are substituted by a motif composed
solely of carbon and hydrogen atoms, the number of carbon atoms of
said substituents ranging from 1 to 5, preferably from 1 to 3, such
as methyl, ethyl, propyl, isopropyl, butyl or isobutyl. The suffix
"oate", as used herein, can interchangeably denote either the
carboxylate ion (COO--) or carboxylic acid (COON). It is not used
to denote an ester. In a particular embodiment, the
3-hydroxyalkanoates are represented by the following formula:
HO--CO--CH.sub.2--C(R.sup.1)(R.sup.2)--OH or
O.sup.---CO--CH.sub.2--C(R.sup.1)(R.sup.2)--OH.
[0024] The term "3-phosphonoxyalkanoate" denotes a molecule which
responds to the following general formula:
C.sub.n+1H.sub.2n+3O.sub.6P,
with 1<n<7, and comprising 3-phosphonoxypropionate as a
common motif, and optionally one or two alkyl substitutions on
carbon 3.
[0025] The term "alkene", as used herein, denotes molecules
composed solely of carbon and hydrogen, containing one
carbon-carbon double bond and having the chemical formula of a
mono-unsaturated hydrocarbon, C.sub.nH.sub.2n, where n equals at
least two. Preferably, n equals at least 3, 4, 5 or 6. Most
preferably n is at most 6. Thus, generally, the term "alkene"
refers to a molecule responding to the formula C.sub.nH.sub.2n,
with 1<n<7.
[0026] In a preferred embodiment alkenes are represented by the
structural formula H.sub.2C.dbd.C(R.sup.1)(R.sup.2) wherein R.sup.1
and R.sup.2 are selected, independently, from the group consisting
of a hydrogen atom and a linear or branched alkyl radical, so that
the total number of carbon atoms in the alkene molecule is at most
6.
[0027] Preferred examples of alkene compounds according to the
invention are in particular ethylene, propylene, isobutylene, and
isoamylene (FIG. 4), or else 1-butylene and 1-amylene.
[0028] "Carbon source", as used herein, denotes any carbon compound
that can be used as substrate for the organisms according to the
invention. Said term includes glucose or any other hexose, xylose
or any other pentose, polyols such as glycerol, sorbitol or
mannitol, or else polymers such as starch, cellulose or
hemicellulose, or else poly-3-hydroxyalkanoates like
poly-3-hydroxybutyrate. It may be any substrate allowing the growth
of microorganisms, such as formate for example. It may also be
CO.sub.2 in the case where the organisms are capable of carrying
out photosynthesis.
[0029] "Recombinant", as used herein, denotes the artificial
genetic modification of an organism, either by addition, removal,
or modification of a chromosomal or extra-chromosomal gene or
regulatory motif such as a promoter, or by fusion of organisms, or
by addition of a vector of any type, for example plasmidic. The
term "recombinant expression" denotes the production of a protein
involving a genetic modification, preferably in order to produce a
protein of exogenous or heterologous origin with respect to its
host, that is, which does not naturally occur in the production
host, or in order to produce a modified or mutated endogenous
protein.
[0030] "Overexpression" or "overexpressing", as used herein,
denotes the recombinant expression of a protein in a host organism,
preferably originating from an organism different from the one in
which it is expressed, increased by at least 10% and preferably by
20%, 50%, 100%, 500% and possibly more as compared to the natural
expression of said protein occurring in said host organism. This
definition also encompasses the case where there is no natural
expression of said protein.
[0031] A "co-substrate" is a compound or molecule added to the
enzymatic reaction, so as to improve certain parameters thereof,
and above all the activity thereof, said product and the principal
substrate being consumed in equal amounts. The co-substrate must
therefore be added to the reaction at a concentration comparable to
that of the principal substrate. Depending on the enzyme, the
presence of a co-substrate may be required for the enzymatic
reaction.
[0032] A "cofactor" is a product added to the enzymatic reaction,
so as to improve certain parameters thereof and above all to
improve the activity thereof, said product not being consumed
during the reaction, and therefore needing only to be added at a
low concentration, proportional to the amount of enzyme, said
concentration therefore being referred to as "catalytic".
[0033] A "part" of an amino acid sequence denotes a fragment
comprising at least 10, preferably at least 20, 30, 40 or 50
consecutive amino acid residues of said sequence.
[0034] "Homology", as used herein, denotes the existence of a
similarity between two sequences as measured by the percent
identity between said two sequences. In a preferred embodiment the
term "homology" means sequence identity.
[0035] Chemical compounds are often known by several names,
official or common. Herein, the common names of the molecules are
preferred. Thus: [0036] "ethylene" is used to denote ethene [0037]
"propylene" is used to denote propene [0038] "butylene" is used to
denote butene [0039] "isobutylene" is used to denote
2-methylpropene or isobutene [0040] "amylene" is used to denote
pentene [0041] "isoamylene" is used to denote 2-methyl-but-1-ene or
isopentene [0042] "propionate" is used to denote propanoic acid or
the propanoate ion [0043] "butyrate" is used to denote butanoic
acid or the butanoate ion [0044] "valerate" is used to denote
pentanoic acid or the pentanoate ion.
[0045] The present invention describes a method for producing
alkene compounds starting from a 3-hydroxyalkanoate through a
biological process, in particular an enzymatic process, in which
two types of enzymes are combined in order to increase the
efficiency of the production rate. More specifically, the present
invention relates to a method for producing an alkene,
characterized in that it comprises the conversion of a
3-hydroxyalkanoate into said alkene by [0046] (i) a first enzyme
having an activity of converting the 3-hydroxyalkanoate into the
corresponding 3-phosphonoxyalkanoate; and [0047] (ii) a second
enzyme being different from the first enzyme and having an activity
of converting said 3-phosphonoxyalkanoate into said alkene.
[0048] As mentioned above, WO 2010/001078 describes a process for
producing alkenes by enzymatic conversion of 3-hydroxyalkanoic
acids with an enzyme having the activity of a decarboxylase. It has
been described in WO 2010/001078 that generally the conversion of a
3-hydroxyalkanoate into an alkene by an enzyme having a
decarboxylase activity, e.g. a mevalonate diphosphate (MDP)
decarboxylase (E.C. 4.1.1.33) takes place by the conversion of the
3-hydroxyalkanoate into the corresponding 3-phosphonoxyalkanoate
which is then decarboxylated to lead to the corresponding alkene.
The generic reaction carried out by MDP decarboxylase using various
3-hydroxyalkanoates is depicted in FIG. 2B.
[0049] It has now been found that different decarboxylases, in
particular mevalonate diphosphate decarboxylases, catalyze the two
above mentioned steps with different efficiencies, i.e. that some
decarboxylases catalyze the first step with a higher efficiency
than other decarboxylases and that some decarboxylases show a
preference for the second step, i.e. the decarboxylation step, and
that therefore the efficiency of the conversion of the
3-hydroxyalkanoate into the alkene as described in WO 2010/001078
can be significantly increased by combining corresponding enzymes.
Thus, the present invention in particular relates to a method for
achieving a higher efficiency in the enzymatic production of
alkenes from 3-hydroxyalkanoates, i.e. a method for improving the
efficiency of such an enzymatic production.
[0050] The term "an enzyme having an activity of converting the
3-hydroxyalkanoate into the corresponding 3-phosphonoxyalkanoate"
means an enzyme which can phosphorylate a 3-hydroxyalkanoate into
the corresponding 3-phosphonoxyalkanoate. The phosphate group comes
preferably from an ATP molecule.
[0051] This activity can, e.g., be measured as described in the
attached Examples, in particular Example 5. One possibility is thus
to incubate the respective enzyme with the 3-hydroxyalkanoate and
ATP and to measure the production of ADP (which reflects the
production of the corresponding 3-phosphonoxyalkanoate). Assays for
measuring the production of ADP are known to the person skilled in
the art. One of these methods is the pyruvate kinase/lactate
dehydrogenase assay described in Example 5. In this case the assay
measures the rate of NADH absorbance decrease at 340 nm which is
proportional to the ADP quantity. In a preferred embodiment the
term "an enzyme having an activity of converting the
3-hydroxyalkanoate into the corresponding 3-phosphonoxyalkanoate"
means an enzyme which can convert 3-hydroxyisovalerate and ATP into
3-phosphonoxyisovalerate and ADP. Even more preferably such an
enzyme can catalyze the reaction of converting the
3-hydroxyalkanoate into the corresponding 3-phosphonoxyalkanoate,
preferably the reaction of converting 3-hydroxyisovalerate and ATP
into 3-phosphonoxyisovalerate and ADP, with a K.sub.M of 10 mM or
lower, e.g. with a K.sub.M of 5 mM or lower, preferably of 1 mM or
lower and even more preferably of 0.1 mM or lower. In a
particularly preferred embodiment such an enzyme can catalyze the
reaction of converting the 3-hydroxyalkanoate into the
corresponding 3-phosphonoxyalkanoate, preferably the reaction of
converting 3-hydroxyisovalerate and ATP into
3-phosphonoxyisovalerate and ADP, with a k.sub.cat of at least 0.2
s.sup.-1, preferably with a k.sub.cat of at least 0.5 s.sup.-1,
particularly preferred with a k.sub.cat of at least 1.0 s.sup.-1,
more preferred of at least 2.0 s.sup.-1 and even more preferred
with a k.sub.cat of at least 5.0 s.sup.-1.
[0052] In a particularly preferred embodiment the capacity to
convert 3-hydroxyisovalerate and ATP into 3-phosphonoxyisovalerate
and ADP is measured in an assay as described in Example 5.
[0053] The term "an enzyme having an activity of converting said
3-phosphonoxyalkanoate into said alkene" means an enzyme which can
catalyze a reaction by which there is a decarboxylation and
dephosporylation of the 3-phosphonoxyalkanoate thereby leading to
the corresponding alkene.
[0054] This activity can, e.g., be measured as described in the
appended Examples, in particular in Example 8. One possibility is
thus to incubate the respective enzyme with the corresponding
phosphonoxyalkanoate under conditions which in principle allow the
decarboxylation and the dephosphorylation and to detect the
production of the corresponding alkene, e.g. by gas chromatography.
In a preferred embodiment the term "an enzyme having an activity of
converting said 3-phosphonoxyalkanoate into said alkene" means an
enzyme which can convert 3-phosphonoxyisovalerate into isobutene,
preferably under the conditions described in Example 8. Even more
preferably such an enzyme can catalyze the reaction of converting
the 3-phosphonoxyalkanoate into the corresponding alkene (via
decarboxylation and dephosphorylation) with a K.sub.M of 100 mM or
lower, e.g. with a K.sub.M of 75 mM or lower, or with a K.sub.M of
50 mM or lower, preferably of 10 mM or lower or 5 mM or lower or 1
mM or lower, and even more preferably of 0.1 mM or lower. In a
particularly preferred embodiment such an enzyme can catalyze the
reaction of converting the 3-phosphonoxyalkanoate into the
corresponding alkene, preferably the reaction of converting
3-phosphonoxyisovalerate into isobutene, with a k.sub.cat of at
least 10.sup.-6 s.sup.-1, preferably with a k.sub.cat of at least
10.sup.-4 s.sup.-1, e.g. with a k.sub.cat of at least 10.sup.-3
s.sup.-1 or with a k.sub.cat of at least 10's.sup.-1, such as with
a k.sub.cat of at least 10.sup.-1 s.sup.-1, for example with a
k.sub.cat of at least 0.2 s.sup.-1, preferably with a k.sub.cat of
at least 0.5 s.sup.-1, particularly preferred with a k.sub.cat of
at least 1.0 s.sup.-1, more preferred of at least 2.0 s.sup.-1 and
even more preferred with a k.sub.cat of at least 5.0 s.sup.-1.
[0055] In a particularly preferred embodiment the capacity to
convert 3-phosphonoxyisovalerate into isobutene is measured in an
assay as described in Example 8.
[0056] In one preferred embodiment an enzyme mentioned in (i) and
(ii), above, is an enzyme which is considered by NCBl or an
equivalent engine as having a COG3407 domain.
[0057] In a preferred embodiment of the method according to the
invention the first enzyme (i) having an activity of converting the
3-hydroxyalkanoate into the corresponding 3-phosphonoxyalkanoate is
selected from the group consisting of [0058] (A) a protein
comprising the amino acid sequence as shown in SEQ ID NO: 1 or a
protein comprising an amino acid sequence which is at least 15%
identical to the amino acid sequence shown in SEQ ID NO: 1 and
showing an activity of converting the 3-hydroxyalkanoate into the
corresponding 3-phosphonoxyalkanoate which is at least as high as
the corresponding activity of the protein having the amino acid
sequence shown in SEQ ID NO: 1; [0059] (B) a protein comprising the
amino acid sequence as shown in SEQ ID NO: 2 or a protein
comprising an amino acid sequence which is at least 15% identical
to the amino acid sequence shown in SEQ ID NO: 2 and showing an
activity of converting the 3-hydroxyalkanoate into the
corresponding 3-phosphonoxyalkanoate which is at least as high as
the corresponding activity of the protein having the amino acid
sequence shown in SEQ ID NO: 2; [0060] (C) a protein comprising the
amino acid sequence as shown in SEQ ID NO: 3 or a protein
comprising an amino acid sequence which is at least 15% identical
to the amino acid sequence shown in SEQ ID NO: 3 and showing an
activity of converting the 3-hydroxyalkanoate into the
corresponding 3-phosphonoxyalkanoate which is at least as high as
the corresponding activity of the protein having the amino acid
sequence shown in SEQ ID NO: 3; and [0061] (D) a protein comprising
the amino acid sequence as shown in SEQ ID NO: 4 or a protein
comprising an amino acid sequence which is at least 15% identical
to the amino acid sequence shown in SEQ ID NO: 4 and showing an
activity of converting the 3-hydroxyalkanoate into the
corresponding 3-phosphonoxyalkanoate which is at least as high as
the corresponding activity of the protein having the amino acid
sequence shown in SEQ ID NO: 4.
[0062] SEQ ID NO: 1 shows the amino acid sequence of an enzyme from
Picrophilus torridus DSM 9790 (GenBank accession number AAT43941;
Swissprot/TrEMBL accession number Q6KZB1).
[0063] SEQ ID NO: 2 shows the amino acid sequence of an enzyme from
Thermoplasma acidophilum (GenBank accession number CAC12426;
Swissprot/TrEMBL accession number Q9HIN1).
[0064] SEQ ID NO: 3 shows the amino acid sequence of an enzyme from
Thermoplasma volcanium (GenBank accession number BAB59465;
Swissprot/TrEMBL accession number Q97BY2).
[0065] SEQ ID NO: 4 shows the amino acid sequence of an enzyme from
Ferroplasma acidarmanus fer1 (GenBank accession number
ZP.sub.--05571615).
[0066] In a further preferred embodiment of the method according to
the invention the second enzyme (ii) having an activity of
converting said 3-phosphonoxyalkanoate into said alkene is selected
from the group consisting of [0067] (a) a protein comprising the
amino acid sequence as shown in SEQ ID NO: 5 or a protein
comprising an amino acid sequence which is at least 15% identical
to the amino acid sequence shown in SEQ ID NO: 5 and showing an
activity of converting said 3-phosphonoxyalkanoate into said alkene
which is at least as high as the corresponding activity of the
protein having the amino acid sequence shown in SEQ ID NO: 5;
[0068] (b) a protein comprising the amino acid sequence as shown in
SEQ ID NO: 6 or a protein comprising an amino acid sequence which
is at least 15% identical to the amino acid sequence shown in SEQ
ID NO: 6 and showing an activity of converting said
3-phosphonoxyalkanoate into said alkene which is at least as high
as the corresponding activity of the protein having the amino acid
sequence shown in SEQ ID NO: 6; [0069] (c) a protein comprising the
amino acid sequence as shown in SEQ ID NO: 7 or a protein
comprising an amino acid sequence which is at least 15% identical
to the amino acid sequence shown in SEQ ID NO: 7 and showing an
activity of converting said 3-phosphonoxyalkanoate into said alkene
which is at least as high as the corresponding activity of the
protein having the amino acid sequence shown in SEQ ID NO: 7;
[0070] (d) a protein comprising the amino acid sequence as shown in
SEQ ID NO: 8 or a protein comprising an amino acid sequence which
is at least 15% identical to the amino acid sequence shown in SEQ
ID NO: 8 and showing an activity of converting said
3-phosphonoxyalkanoate into said alkene which is at least as high
as the corresponding activity of the protein having the amino acid
sequence shown in SEQ ID NO: 8; [0071] (e) a protein comprising the
amino acid sequence as shown in SEQ ID NO: 9 or a protein
comprising an amino acid sequence which is at least 15% identical
to the amino acid sequence shown in SEQ ID NO: 9 and showing an
activity of converting said 3-phosphonoxyalkanoate into said alkene
which is at least as high as the corresponding activity of the
protein having the amino acid sequence shown in SEQ ID NO: 9;
[0072] (f) a protein comprising the amino acid sequence as shown in
SEQ ID NO: 10 or a protein comprising an amino acid sequence which
is at least 15% identical to the amino acid sequence shown in SEQ
ID NO: 10 and showing an activity of converting said
3-phosphonoxyalkanoate into said alkene which is at least as high
as the corresponding activity of the protein having the amino acid
sequence shown in SEQ ID NO: 10; [0073] (g) a protein comprising
the amino acid sequence as shown in SEQ ID NO: 11 or a protein
comprising an amino acid sequence which is at least 15% identical
to the amino acid sequence shown in SEQ ID NO: 11 and showing an
activity of converting said 3-phosphonoxyalkanoate into said alkene
which is at least as high as the corresponding activity of the
protein having the amino acid sequence shown in SEQ ID NO: 11;
[0074] (h) a protein comprising the amino acid sequence as shown in
SEQ ID NO: 12 or a protein comprising an amino acid sequence which
is at least 15% identical to the amino acid sequence shown in SEQ
ID NO: 12 and showing an activity of converting said
3-phosphonoxyalkanoate into said alkene which is at least as high
as the corresponding activity of the protein having the amino acid
sequence shown in SEQ ID NO: 12; [0075] (i) a protein comprising
the amino acid sequence as shown in SEQ ID NO: 13 or a protein
comprising an amino acid sequence which is at least 15% identical
to the amino acid sequence shown in SEQ ID NO: 13 and showing an
activity of converting said 3-phosphonoxyalkanoate into said alkene
which is at least as high as the corresponding activity of the
protein having the amino acid sequence shown in SEQ ID NO: 13;
[0076] (j) a protein comprising the amino acid sequence as shown in
SEQ ID NO: 14 or a protein comprising an amino acid sequence which
is at least 15% identical to the amino acid sequence shown in SEQ
ID NO: 14 and showing an activity of converting said
3-phosphonoxyalkanoate into said alkene which is at least as high
as the corresponding activity of the protein having the amino acid
sequence shown in SEQ ID NO: 14; and [0077] (k) a protein
comprising the amino acid sequence as shown in SEQ ID NO: 15 or a
protein comprising an amino acid sequence which is at least 15%
identical to the amino acid sequence shown in SEQ ID NO: 15 and
showing an activity of converting said 3-phosphonoxyalkanoate into
said alkene which is at least as high as the corresponding activity
of the protein having the amino acid sequence shown in SEQ ID NO:
15.
[0078] SEQ ID NO: 5 shows the amino acid sequence of an enzyme
cloned from Streptococcus gordonii. SEQ ID NO: 6 shows the amino
acid sequence of an enzyme from Streptococcus gordonii str. Challis
substr. CH1 (GenBank accession number AAT43941; Swissprot/TrEMBL
accession number A8UU9). SEQ ID NO: 7 shows the amino acid sequence
of an enzyme from Streptococcus infantarius subsp infantarius ATCC
BAA-102 (GenBank accession number EDT48420.1; Swissprot/TrEMBL
accession number B1SCG0). SEQ ID NO: 8 shows the amino acid
sequence of an enzyme from Homo sapiens (GenBank accession number
AAC50440.1; Swissprot/TrEMBL accession number P53602.1). SEQ ID NO:
9 shows the amino acid sequence of an enzyme from Lactobacillus
delbrueckii (GenBank accession number CAI97800.1; Swissprot/TrEMBL
accession number Q1GAB2). SEQ ID NO: 10 shows the amino acid
sequence of an enzyme from Streptococcus mitis (strain B6) (GenBank
accession number CBJ22986.1). SEQ ID NO: 11 shows the amino acid
sequence of an enzyme from Streptococcus gallolyticus UCN34
(GenBank accession number CBI13757.1). SEQ ID NO: 12 shows the
amino acid sequence of an enzyme from Streptococcus sanguinis SK36
(GenBank accession number ABN43791.1). SEQ ID NO: 13 shows the
amino acid sequence of an enzyme from Streptococcus sp. M143
(GenBank accession number EFA24040.1). SEQ ID NO: 14 shows the
amino acid sequence of an enzyme from Streptococcus suis 89/1591
(GenBank accession number EEF63672.1). SEQ ID NO: 15 shows the
amino acid sequence of an enzyme from Streptococcus salivarius
SK126 (GenBank accession number EEK09252).
[0079] In a preferred embodiment of the method according to the
invention the first enzyme (i) is as defined in (A) above and the
second enzyme (ii) is as defined in (a) or (b) mentioned above,
even more preferably the second enzyme is as defined in (f), (g),
(h), (i), (j) or (k) mentioned above. As illustrated in the
examples, the combination of these enzymes is particularly
efficient at producing alkene compounds according to the present
invention.
[0080] In another preferred embodiment of the method according to
the invention the second enzyme (ii) having an activity of
converting said 3-phosphonoxyalkanoate into said alkene is selected
from any one of the proteins listed in the following Table or from
a protein comprising an amino acid sequence which is at least 15%
identical to the amino acid sequence of such a protein and showing
an activity of converting said 3-phosphonoxyalkanoate into said
alkene which is at least as high as the corresponding activity of
said protein.
TABLE-US-00001 TABLE 1 Organism Ref sequence GenBank Methanosarcina
mazei AAM31457.1 Methanocaldococcus jannaschii AAB98390.1
Staphylococcus saprophyticus BAE19266.1 Streptococcus agalactiae
EA073731.1 Enterococcus faecalis AA080711.1 Flavobacterium
johnsoniae ABQ04421.1 Bdellovibrio bacteriovorus CAE79505.1
Chloroflexus aurantiacus A9WEU8.1 Legionella pneumophila CAH13175.1
Listeria monocytogenes EAL09343.1 Metallosphaera sedula ABP95731.1
Staphylococcus epidermidis AA003959.1 Streptococcus thermophilus
AAV60266.1 Bacillus coagulans EAY45229.1 Chloroflexus aggregans
EAV09355.1 Lactobacillus brevis ABJ64001.1 Lactobacillus fermentum
BAG27529.1 Lactobacillus plantarum CAD64155.1 Lactobacillus
salivarius ABD99494.1 Lactococcus lactis sp. lactis AAK04503.1
Dichelobacter nodosus ABQ14154.1 Flavobacterium psychrophilum
CAL42423.1 Streptococcus pneumoniae EDT95457.1 Streptococcus
pyogenes AAT86835.1 Streptococcus suis ABP91444.1 Staphylococcus
haemolyticus BAE05710.1 Streptococcus equi ACG62435.1 Arabidopsis
thaliana AAC67348.1 Borrelia afzelii ABH01961.1 Encephalitozoon
cuniculi CAD25409.1 Streptomyces sp. BAB07791.1 Streptococcus
agalactiae EA073731.1 Streptococcus uberis CAR41735.1 Gallus gallus
XP_423130 Salmo salmar ACI34234 Natromonas pharaonis CAI48881.1
Haloarcula marismortui AAV46412.1 Haloquadratum walsbyi
CAJ51653.1
[0081] As mentioned above, not only the proteins having the
specifically mentioned amino acid sequences listed in the
respective SEQ ID NOs or in Table 1 can be used, but also proteins
which are considered by NCBl or an equivalent engine as having a
COG3407 domain and, more preferred, proteins the amino acid
sequence of which shows a homology of at least 15% to the
specifically mentioned amino acid sequence and which have a
respective enzymatic activity at least as high as the activity of a
protein having the specifically mentioned amino acid sequence.
Preferred enzymes advantageously have at least x % homology,
wherein x is selected from the group consisting of 20, 25, 20, 35,
40, 45, 50, 55 and 60. In a further preferred embodiment the enzyme
has at least 65% sequence homology, preferably at least 70%, more
preferably at least 75%, even more preferably, at least 80, 85, 90,
95, 96, 97, 98 or 99% homology to one of the sequences shown in SEQ
ID NO: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14 or 15 or to
one of the sequences shown in Table 1. The percent of sequence
homology can be determined by different methods and by means of
software programs known to one of skill in the art, such as for
example the CLUSTAL method or BLAST and derived software, or by
using a sequence comparison algorithm such as that described by
Needleman and Wunsch (J. Mol. Biol., 1970, 48:443) or Smith and
Waterman (J. Mol. Biol., 1981, 147:195).
[0082] Such proteins showing the indicated degree of homology can,
e.g., be other enzymes which occur naturally or which have been
prepared synthetically. They include in particular enzymes which
can be selected for their ability to produce alkenes according to
the invention. Thus, a selection test comprises contacting the
purified enzyme, or a microorganism producing the enzyme, with the
substrate of the reaction and measuring the production of the
respective compound, i.e. the 3-phosphonoxyalkanoate or the alkene.
Such tests are described in the experimental section. Such
selection tests can also be used to screen for enzymes with an
optimized enzymatic activity for the substrate to be converted into
the 3-phosphonoxyalkanoate or the alkene, i.e. having an optimized
activity with respect to one or more 3-hydroxyalkanoates or
3-phosphonoxyalkanoates.
[0083] Such screening methods are well-known in the art and
include, e.g. protein engineering techniques such as random
mutagenesis, massive mutagenesis, site-directed mutagenesis, DNA
shuffling, synthetic shuffling, in vivo evolution, or complete
synthesis of genes and subsequent screening for the desired
enzymatic activity.
[0084] The enzyme used in the invention can thus be natural or
synthetic, and produced by chemical, biological or genetic means.
It can also be chemically modified, for example in order to improve
its activity, resistance, specificity, purification, or to
immobilize it on a support.
[0085] It has been found that enzymes which are able to catalyze
the above described reactions for converting a 3-hydroxyalkanoate
into an alkene via a 3-phospho-hydroxyalkanoate are often enzymes
which can be classified in the phylogenetic superfamily of
mevalonate diphosphate (MDP) decarboxylases (enzyme nomenclature EC
4.1.1.33). MDP decarboxylase is an enzyme involved in cholesterol
biosynthesis. Said enzyme has been isolated from a variety of
organisms including animals, fungi, yeasts and some bacteria. It
can also be expressed by some plants (Lalitha et al.,
Phytochemistry 24 (11), (1985), 2569-2571). Many genes encoding
this enzyme have been cloned and sequenced. These enzymes are
generally composed of 300 to 400 amino acids and use ATP as
co-substrate, which is converted during the reaction to ADP and
inorganic phosphate. The phosphate group is transferred from the
ATP molecule to the tertiary alcohol of mevalonate diphosphate,
releasing ADP. The reaction intermediate phosphorylated on the
3-hydroxyl group then undergoes elimination of the phosphate group,
in the physiological case releasing isopentenyl diphosphate (FIG.
2).
[0086] Accordingly, in a preferred embodiment, the enzyme defined
in (i) or (ii) above, is a MDP decarboxylase. In the context of the
present invention a MDP decarboxylase is defined as an enzyme which
can at least catalyze the conversion of
5-diphospho-3-phosphomevalonate into isopentenyl-5-diphosphate and
CO.sub.2 or which can at least catalyze the reaction of converting
mevalonate diphosphate and ATP into 5-diphospho-3-phosphomevalonate
and ADP. Preferably, such an enzyme can catalyze both
reactions.
[0087] In another preferred embodiment the enzyme defined in (i)
above, is an enzyme as defined in (i) (B). The sequence shown in
SEQ ID NO: 2 represents an enzyme identified in Thermoplasma
acidophilum. In Genbank this enzyme is classified as a mevalonate
diphosphate decarboxylase. However, it is known from Chen and
Poulter (Biochemistry 49 (2010), 207-217) that in Th. acidophilum
there exists an alternative mevalonate pathway which involves the
action of a mevalonate-5-monophosphate decarboxylase. Thus, it is
possible that the enzyme represented by SEQ ID NO: 2 actually
represents a mevalonate-5-monophosphate decarboxylase. The same may
hold true for other archae bacteria. Therefore, in another
preferred embodiment the enzyme defined in (i) or (ii) above, is a
mevalonate-5-monophosphate decarboxylase. Such an enzyme is capable
of converting mevalonate-5-monophosphate into
isopentenylpyrophosphate.
[0088] In preferred embodiments of the invention: [0089]
3-hydroxypropionate is converted via 3-phosphonoxypropionate into
ethylene; or [0090] 3-hydroxybutyrate is converted via
3-phosphonoxybutyrate into propylene; or [0091] 3-hydroxyvalerate
is converted via 3-phosphonoxyvalerate into 1-butylene; or [0092]
3-hydroxy-3-methylbutyrate (or 3-hydroxyisovalerate) is converted
via 3-phosphonoxy-3-methylbutyrate (3-phosphonoxyisovalerate) into
isobutylene; or [0093] 3-hydroxy-3-methylvalerate is converted via
3-phosphonoxy-3-methylvalerate into isoamylene.
[0094] The method according to the invention can be carried out in
vitro, in the presence of isolated enzymes (or enzyme systems
additionally comprising one or more cofactors). In vitro preferably
means in a cell-free system.
In one embodiment, the enzymes employed in the method are used in
purified form to convert 3-hydroxyalkanoates to alkenes. However,
such a method may be costly, since enzyme and substrate production
and purification costs are high. Thus, in another preferred
embodiment, the enzymes employed in the method are present in the
reaction as a non-purified extract, or else in the form of
non-lysed bacteria, so as to economize on protein purification
costs. However, the costs associated with such a method may still
be quite high due to the costs of producing and purifying the
substrates.
[0095] Accordingly, in one preferred embodiment, the enzymes,
native or recombinant, purified or not, are used to convert a
3-hydroxyalkanoate to an alkene. To do this, the enzymes are
incubated in the presence of the substrate in physicochemical
conditions allowing the enzymes to be active, and the incubation is
allowed to proceed for a sufficient period of time. At the end of
the incubation, one optionally measures the presence of the alkene
by using any detection system known to one of skill in the art such
as gas chromatography or colorimetric tests for measuring the
formation of the alkene product, or of free phosphate, or else for
measuring the disappearance of the 3-hydroxyalkanoate substrate or
of ATP.
[0096] In a preferred embodiment, cofactors are added so as to best
mimic the natural reaction or so as to provide steric or electronic
complementation in the catalytic cleft. For example, if one of the
enzymes used in the method according to the invention is an enzyme
which naturally uses mevalonate disphosphate (MDP) as a substrate,
the structure of 3-hydroxyalkanoates leaves a large space in the
catalytic cleft empty during enzyme-substrate binding since
generally a 3-hydroxyalkanoate corresponds to a fragment of MDP.
Filling this space with a cofactor to replace the missing part of
the substrate has the purpose of most closely mimicking the MDP
molecule. As the cofactor is not modified during the reaction, it
will therefore be added only in catalytic amounts. In the case
where the substrate of the reaction is 3-hydroxypropionate, the
complementary cofactor will be propyl diphosphate. In the case
where the substrate is 3-hydroxybutyrate or 3-hydroxy-3-methyl
butyrate, the complementary cofactor will be ethyl diphosphate. In
the case where the substrate is 3-hydroxyvalerate or
3-hydroxy-3-methylvalerate, the complementary cofactor will be
methyl diphosphate. These different molecules are shown in FIG. 5.
By chance, it may happen that the complementary cofactor of a
reaction has a positive effect on the reaction of another
substrate. Generally, the cofactor can be any molecule comprising a
phosphoanhydride, and therefore having the general global formula
R--PO.sub.2H--O--PO.sub.3H.sub.2, in which R is in particular H, a
linear, branched or cyclic alkyl group, preferably having from 1 to
10 or from 1 to 5 carbon atoms, or any other monovalent organic
group. The analogous motifs corresponding to methylene
diphosphonate monoesters, having the general formula
R--O--PO.sub.2H--CH.sub.2--PO.sub.3H.sub.2 in which
phosphyanhydride is replaced by a methylene bridge having the
advantage of not being hydrolyzed, are also part of the invention.
More generally, the cofactors can be monophosphate, or even
phosphate-free, analogs of the previous molecules, or else any
other molecule that can improve the reaction yield by providing
steric or electronic complementation in the enzyme catalytic site.
The cofactor is advantageously selected from the group consisting
of the pyrophosphate ion, methyl diphosphate, ethyl diphosphate, or
propyl diphosphate.
[0097] In a preferred embodiment, the conversion occurs in the
presence of a co-substrate, said co-substrate preferably being a
compound containing a phosphoanhydride, and preferably being ATP,
an rNTP, a dNTP or a mixture of several of these molecules, a
polyphosphate, or pyrophosphate. The co-substrate is generally
present in the host. However, in another particular embodiment, a
co-substrate can be added to the reaction, preferably selected from
the group consisting of ATP, an rNTP, a dNTP, a mixture of several
rNTPs or dNTPs, a polyphosphate, and preferably pyrophosphate, or a
compound containing a phosphoanhydride (represented by the general
formula X--PO.sub.3H.sub.2 of FIG. 2).
Although the decarboxylation step, i.e. the reaction defined as
(ii) herein-above, does not require ATP consumption, it could be
shown that the presence of ATP in the reaction could be beneficial.
This has been demonstrated in Example 7, using
3-phosphonoxyisovalerate as a substrate. It is assumed that ATP
might have an effect on the folding of the protein by the binding
of ATP to the ATP-binding site of the diphosphomevalonate
decarboxylase. In fact, this can be observed by eye: the purified
enzyme has a tendency to precipitate, and the addition of ATP
prevents this effect. It is considered that not only ATP but also
other similar compounds like dATP, ADP, AMP or other NTPs or dNTPs
have this effect. Thus, in a preferred embodiment, the method
according to the present invention is carried with ATP, dATP, ADP,
AMP or an NTP other than ATP or a dNTP as co-substrate.
[0098] In another preferred embodiment the method according to the
invention is carried out in culture, in the presence of an
organism, preferably a microorganism, producing the enzymes. Thus,
in such an embodiment of the invention, an organism, preferably a
microorganism, that produces the enzymes specified in (i) and (ii)
above is used. In a preferred embodiment, the (micro)organism is
recombinant in that the enzymes specified in (i) and (ii) produced
by the host are heterologous relative to the production host. The
method can thus be carried out directly in the culture medium,
without the need to separate or purify the enzymes. In an
especially advantageous manner, a (micro)organism is used having
the natural or artificial property of endogenously producing one or
more 3-hydroxyalkanoates, and also expressing or overexpressing the
enzymes specified in (i) and (ii) above, natural or modified, so as
to produce alkenes directly from a carbon source present in
solution.
[0099] For example, the method according to the invention can be
carried out by using microorganisms which produce one or more
3-hydroxyalkanoates [for example Alcaligenes eutrophus or Bacillus
megaterium, or else an E. coli strain genetically modified so as to
produce said product(s)] and which have been genetically engineered
such that they overexpress the enzymes as defined in (i) and (ii)
above, said enzymes preferably originating from an organism
different from the host microorganism. The genetic modification can
consist, e.g. in integrating the corresponding genes encoding the
enzymes into the chromosome, expressing the enzymes from a plasmid
containing a promoter upstream of the enzyme-coding sequence, the
promoter and coding sequence preferably originating from different
organisms, or any other method known to one of skill in the art.
Alternatively, other bacteria or yeasts may have specific
advantages and can be chosen. For instance, a yeast such as
Saccharomyces cerevisiae, an extremophilic bacterium such as
Thermus thermophilus, or anaerobic bacteria from the family
Clostridiae, microalgae, or photosynthetic bacteria can be
used.
[0100] The organisms used in the invention can be prokaryotes or
eukaryotes, preferably, they are microorganisms such as bacteria,
yeasts, fungi or molds, or plant cells or animal cells. In a
particular embodiment, the microorganisms are bacteria, preferably
of the genus Escherichia, Alcaligenes or Bacillus and even more
preferably of the species Escherichia coli, Alcaligenes eutrophus
or Bacillus megaterium.
[0101] In another preferred embodiment, the microorganisms are
recombinant bacteria of the genus Escherichia, preferably of the
species Escherichia coli, having been modified so as to
endogenously produce one or more 3-hydroxyalkanoates, and
converting them to alkenes.
[0102] In a further preferred embodiment the microorganism is a
fungus, more preferably a fungus of the genus Saccharomyces,
Schizosaccharomyces, Aspergillus or Trichoderma and even more
preferably of the species Saccharomyces cerevisiae,
Schizosaccharomyces pombe, Aspergillus niger or of the species
Trichoderma reesei. In a particularly preferred embodiment the
microorganism is a recombinant yeast producing 3-hydroxyalkanoates
and converting them to alkenes due to the expression of the enzymes
specified in (i) and (ii) above.
[0103] In another preferred embodiment, the method according to the
invention makes use of a photosynthetic microorganism expressing
the enzymes as specified in (i) and (ii) above. Preferably, the
microorganism is a photosynthetic bacterium, or a microalgae. Even
more preferably such a microorganism has the natural or artificial
property of endogenously producing one or more 3-hydroxyalkanoates.
In this case the microorganism would be capable of producing
alkenes directly from CO.sub.2 present in solution.
[0104] It is also conceivable to use in the method according to the
invention one microorganism that produces an enzyme as defined in
(i) above and another microorganism which produces an enzyme as
defined in (ii) above. Moreover, in a further embodiment at least
one of the microorganisms is capable of producing one or more
3-hydroxyalkanoates or, in an alternative embodiment, a further
microorganism is used in the method which is capable of producing
one or more 3-hydroxyalkanoates.
[0105] In another preferred embodiment the method according to the
invention makes use of a multicellular organism expressing the
enzymes as defined in (i) and (ii) above. Examples for such
organisms are plants or animals.
[0106] In a particular embodiment, the method involves culturing
microorganisms in standard culture conditions (30-37.degree. C. at
1 atm, in a fermenter allowing aerobic growth of the bacteria) or
non-standard conditions (higher temperature to correspond to the
culture conditions of thermophilic organisms, for example).
[0107] In a further preferred embodiment the method of the
invention is carried out in microaerophilic conditions. This means
that the quantity of injected air is limiting so as to minimize
residual oxygen concentrations in the gaseous effluents containing
the alkene hydrocarbons.
[0108] In another preferred embodiment the method according to the
invention furthermore comprises the step of collecting gaseous
alkenes degassing out of the reaction, i.e. recovering the products
which degas, e.g., out of the culture. Thus in a preferred
embodiment, the method is carried out in the presence of a system
for collecting alkene under gaseous form during the reaction.
[0109] As a matter of fact, short alkenes, and particularly
ethylene, propylene and butene isomers, adopt the gaseous state at
room temperature and atmospheric pressure.
[0110] The method according to the invention therefore does not
require extraction of the product from the liquid culture medium, a
step which is always very costly when performed at industrial
scale. The evacuation and storage of the gaseous hydrocarbons and
their possible subsequent physical separation and chemical
conversion can be performed according to any method known to one of
skill in the art.
[0111] In a particular embodiment, the method also comprises
detecting the alkene (for example propylene, ethylene or
isobutylene) which is present in the gaseous phase. The presence of
the compound to be produced in an environment of air or another
gas, even in small amounts, can be detected by using various
techniques and in particular by using gas chromatography systems
with infrared or flame ionization detection, or by coupling with
mass spectrometry.
[0112] In a particular embodiment, the alkenes produced by a method
according to the invention are condensed, then optionally reduced,
by using techniques known to one of skill in the art, so as to
produce longer chain alkenes, or longer chain alkanes. For example,
isobutylene can be used to synthesize isooctane: the catalytic
methods for successfully carrying out this reaction have already
been fully described.
[0113] In another embodiment, the method according to the invention
is characterized by the conversion of a carbon source such as
glucose, to 3-hydroxyalkanoate, followed by the conversion of said
3-hydroxyalkanoate into the corresponding alkene. The different
steps of said method are outlined in FIG. 6.
[0114] In a particular embodiment, the method is characterized by
the conversion of polyhydroxyalkanoates into 3-hydroxyalkanoate by
using an enzyme or a suitable physicochemical method, followed by
the conversion of said 3-hydroxyalkanoate into said alkene.
Optionally, the polyhydroxyalkanoate has been produced by a
microorganism or a plant whose metabolic pathways have been
modified to as to produce high yields of polyhydroxyalkanoate.
[0115] In another embodiment, the method according to the invention
comprises the production of alkenes from atmospheric CO.sub.2 or
from CO.sub.2 artificially added to the culture medium. In this
case the method is implemented in an organism which is able to
carry out photosynthesis, such as for example microalgae.
[0116] The present invention also relates to a method for producing
an alkene comprising the step of enzymatically converting a
3-phosphonoxyalkanoate into the corresponding alkene by use of an
enzyme which can catalyze the conversion via decarboxylation and
dephosphorylation.
[0117] As regards the preferred enzyme to be used in such a method,
the same applies as has been set forth above in connection with
(ii) of the method according to the invention as described
herein-above.
[0118] Moreover, also with respect to the other preferred
embodiments described above for the method according to the
invention, the same applies to the method for producing an alkene
from a 3-phosphonoxyalkanoate.
[0119] The present invention also relates to organisms, preferably
microorganisms, which produce at least two enzymes, wherein one
enzyme is selected from (i) as specified above and the other enzyme
is selected from (ii) as specified above. In a preferred embodiment
such an organism is a recombinant organism in the sense that it is
genetically modified due to the introduction of at least one
nucleic acid molecule encoding at least one of the above mentioned
enzymes. Preferably such a nucleic acid molecule is heterologous
with regard to the organism which means that it does not naturally
occur in said organism.
[0120] Thus, the present invention also relates to an organism,
preferably a microorganism, comprising a nucleic acid molecule
coding for an enzyme as defined in (i) above and comprising a
nucleic acid molecule coding for an enzyme as defined in (ii)
above. In a preferred embodiment at least one of the nucleic acid
molecules is heterologous to the organism which means that it does
not naturally occur in said organism. The microorganism is
preferably a bacterium, a yeast or a fungus. In another preferred
embodiment the organism is a plant or non-human animal. As regards
other preferred embodiments, the same applies as has been set forth
above in connection with the method according to the invention.
[0121] Moreover, the present invention also relates to a
composition comprising a microorganism according to the present
invention, a suitable culture medium and a 3-hydroxyalkanoate
compound or a carbon source that can be converted by the
microorganism to a 3-hydroxyalkanoate compound.
[0122] The present invention also relates to the use of a
combination of at least two enzymes, wherein one enzyme is selected
from the following (i) and the other enzyme is selected from the
following (ii) or of an organism, preferably a microorganism,
according to the invention or of a composition according to the
invention, for producing alkene compounds from 3-hydroxyalkanoates,
wherein (i) and (ii) are as follows: [0123] (i) a first enzyme
having an activity of converting the 3-hydroxyalkanoate into the
corresponding 3-phosphonoxyalkanoate; and [0124] (ii) a second
enzyme being different from the first enzyme and having an activity
of converting said 3-phosphonoxyalkanoate into said alkene.
[0125] As regards the preferred embodiments of the different
components recited, the same applies as has been set forth above in
connection with the method according to the invention.
[0126] Other aspects and advantages of the invention will be
described in the following examples, which are given for purposes
of illustration and not by way of limitation.
FIGURES LEGENDS
[0127] FIG. 1: The 3-hydroxypropionate motif.
[0128] FIG. 2: Reaction catalyzed by mevalonate diphosphate
decarboxylase.
[0129] FIG. 3: Examples of 3-hydroxyalkanoates.
[0130] FIG. 4: Production of alkenes from 3-hydroxyalkanoates by
combining two enzymatic steps.
[0131] FIG. 5: Cofactors that can be used in the reaction for the
purpose of structural complementation in the catalytic site of
mevalonate diphosphate decarboxylase.
[0132] FIG. 6: Integrated method for producing an alkene from
glucose.
[0133] FIG. 7: Screening of MDP decarboxylases in a complementation
assay. The reaction catalyzed by the P. torridus (SEQ ID NO:1)
enzyme alone (0.1 mg) without a second enzyme, was taken as
reference.
[0134] FIG. 8: Combined effect of MDP decarboxylase enzymes from P.
torridus (SEQ ID NO:1) and S. gordonii (SEQ ID NO:5) for converting
3-hydroxyisovalerate (HIV) into isobutene (IBN). IBN production was
measured as a function of the concentration of S. gordonii MDP
decarboxylase (SEQ ID NO:5) added to a pre-incubated reaction
mixture of HIV with 100 .mu.g of P. torridus MDP decarboxylase (SEQ
ID NO:1).
[0135] FIG. 9: Screening of enzyme homologs of S. gordonii MDP
decarboxylase (SEQ ID NO:5). The peak area of isobutene obtained
for the reaction with Th. acidophilum (SEQ ID NO:2) (0.1 mg) enzyme
alone (no second enzyme), was used as reference (ratio=1). [0136]
MDP decarboxylases from the Streptococcus genus are particularly
efficient when used in combination with an enzyme of the P.
torridus phylum.
[0137] FIG. 10: Scheme of the ADP quantification assay, monitoring
NADH consumption by the decrease of absorbance at 340 nm.
[0138] FIG. 11: Plot of the velocity as a function of substrate
concentration for the phosphotransferase reaction catalyzed by P.
torridus MDP decarboxylase (SEQ ID NO:1). Initial rates were
computed from the kinetics over the 30 first minutes of the
reaction.
[0139] FIG. 12: Isobutene production from 3-hydroxyisovalerate in
the following assays: [0140] Without enzyme [0141] In the presence
of S. mitis MDP decarboxylase (SEQ ID NO:10) [0142] In the presence
of Th. acidophilum MDP decarboxylase (SEQ ID NO:2) [0143] In the
presence of both Th. acidophilum (SEQ ID NO:2) and S. mitis (SEQ ID
NO:10) enzymes.
[0144] FIG. 13: Scheme for the chemical synthesis of
3-phosphonoxyisovalerate.
[0145] FIG. 14: GC analysis of assays for isobutene production from
3-phosphonoxyisovalerate in the absence and presence of ATP. [0146]
Assays: [0147] 1. Without enzyme, 0 mM ATP [0148] 2. 2 mg/ml
enzyme, 0 mM ATP [0149] 3. Without enzyme, 10 mM ATP [0150] 4. 2
mg/ml enzyme, 10 mM ATP
[0151] The following Examples serve to illustrate the
invention.
EXAMPLES
Example 1
Cloning, Expression and Purification of an MDP Decarboxylase
Library
[0152] A library of 55 genes encoding representatives of the
diphosphomevalonate decarboxylase (MDP decarboxylase) family across
eukaryotic, prokaryotic and archaeal organisms was constructed and
tested to identify the most active candidates for improving
isobutene (IBN) production.
Cloning, Bacterial Cultures and Expression of Proteins.
[0153] The genes encoding mevalonate diphosphate (MDP)
decarboxylase EC 4.1.1.33 were cloned in the pET 25b vector
(Novagen) in the case of eukaryotic genes and in pET 22b (Novagen)
in the case of prokaryotic genes. A stretch of 6 histidine codons
was inserted after the methionine initiation codon to provide an
affinity tag for purification. Competent E. coli BL21(DE3) cells
(Novagen) were transformed with these vectors according to the heat
shock procedure. The transformed cells were grown with shaking (160
rpm) on ZYM-5052 auto-induction medium (Studier F W, Prot. Exp.
Pur. 41, (2005), 207-234) for 6 h at 37.degree. C. and protein
expression was continued at 28.degree. C. overnight (approximately
16 h). The cells were collected by centrifugation at 4.degree. C.,
10,000 rpm for 20 min and the pellets were frozen at -80.degree.
C.
Protein Purification and Concentration.
[0154] The pellets from 200 ml of culture cells were thawed on ice
and resuspended in 5 ml of Na.sub.2HPO.sub.4 pH 8 containing 300 mM
NaCl, 5 mM MgCl.sub.2 and 1 mM DTT. Twenty microliters of lysonase
(Novagen) were added. Cells were incubated 10 minutes at room
temperature and then returned to ice for 20 minutes. Cell lysis was
completed by sonication for 3.times.15 seconds. The bacterial
extracts were then clarified by centrifugation at 4.degree. C.,
10,000 rpm for 20 min. The clarified bacterial lysates were loaded
on PROTINO-1000 Ni-TED column (Macherey-Nagel) allowing adsorption
of 6-His tagged proteins. Columns were washed and the enzymes of
interest were eluted with 4 ml of 50 mM Na.sub.2HPO.sub.4 pH 8
containing 300 mM NaCl, 5 mM MgCl.sub.2, 1 mM DTT, 250 mM
imidazole. Eluates were then concentrated and desalted on Amicon
Ultra-4 10 kDa filter unit (Millipore) and resuspended in 0.25 ml
50 mM Tris-HCl pH 7.4 containing 0.5 mM DTT and 5 mM MgCl.sub.2.
Protein concentrations were quantified according to the Bradford
method. The purity of proteins thus purified varied from 40% to
90%.
Example 2
Screening of the MDP Decarboxylase Library
[0155] MDP decarboxylases were evaluated using a complementation
assay. P. torridus MDP decarboxylase (SEQ ID NO:1) was incubated
together with each tested enzyme from the library.
[0156] The enzymatic assay was carried out under the following
conditions:
50 mM Tris HCl pH 7,0
10 mM MgCl.sub.2
20 mM KCl
40 mM ATP
[0157] 50 mM 3-hydroxyisovalerate (HIV) The pH was adjusted to
7.0
[0158] 100 .mu.g of the MDP decarboxylase from P. torridus (SEQ ID
NO:1) and 1 mg of the MDP decarboxylase to be tested were added to
1 ml of reaction mixture. A reaction mixture containing only 100
.mu.g of P. torridus MDP decarboxylase (SEQ ID NO:1) was used as
reference. The mixture was then incubated without shaking at
45.degree. C. for 90 h in a sealed vial (Interchim).
[0159] One ml of the gaseous phase was collected and injected into
a HP5890 gas chromatograph (HP) equipped with an FID detector and a
CP SilicaPlot column (Varian). Commercial isobutene was used as
reference.
[0160] This screening procedure led to the identification of
several MDP decarboxylase enzymes increasing the isobutene
production rate. As shown in FIG. 7, a higher production of
isobutene was observed for the following MDP decarboxylases.
[0161] Candidate 1:
Accession number Genbank: CA197800 Accession number
SwissProt/TrEMBL: Q1GAB2 Organism: Lactobacillus delbrueckii subsp.
bulgaricus ATCC 11842 (SEQ ID NO:9)
[0162] Candidate 2:
Accession number Genbank: AAC50440.1 Accession number
SwissProt/TrEMBL: P53602.1 Organism: Homo sapiens (SEQ ID NO:8)
[0163] Candidate 3:
Accession number Genbank: ABV09606 Accession number
SwissProt/TrEMBL: A8AUU9 Organism: Streptococcus gordonii str.
Challis substr. CH1 (SEQ ID NO:6)
[0164] The highest production of isobutene was observed with
purified MDP decarboxylase from Streptococcus gordonii.
[0165] This indicated that the two enzymes present in the assay
(the one from P. torridus (SEQ ID NO:1) and the other from S.
gordonii (SEQ ID NO:5)) were performing complementarily the two
steps of reaction producing IBN from HIV: transfer of the terminal
phosphoryl group from ATP to the C3-oxygen of 3-hydroxyisovalerate
followed by combined dephosphorylation-decarboxylation of the
intermediate 3-phosphonoxyisovalerate.
Example 3
Effect of Enzyme Concentration on Isobutene Production Yield
[0166] The effect of Streptococcus gordonii MDP decarboxylase (SEQ
ID NO:5) concentration was assessed under the following
conditions:
50 mM Tris-HCl pH 7,0
10 mM MgCl.sub.2
20 mM KCl
40 mM ATP
[0167] 50 mM 3-hydroxyisovalerate (HIV) The pH was adjusted to
7,0
[0168] 100 .mu.g of MDP decarboxylase from P. torridus (SEQ ID
NO:1) and a varying amount (from 0 to 1 mg) of purified MDP
decarboxylase from Streptococcus gordonii (SEQ ID NO:5) were added
to 1 ml of reaction mixture. The mixture was then incubated without
shaking at 45.degree. C. for 90 h in a sealed vial (Interchim).
[0169] One ml of the headspace phase was collected and injected
into a HP5890 gas chromatograph (HP) equipped with an FID detector
and a CP SilicaPlot column (Varian). Commercial isobutene was used
as reference.
[0170] Increasing the S. gordonii enzyme (SEQ ID NO:5)
concentration resulted in an increase of the amount of isobutene
produced (FIG. 8).
Example 4
Screening of a Library of Streptococcus gordonii MDP Decarboxylase
Homologs
[0171] Using the BLAST online program hosted by NCBI, sequences
were searched against non redundant protein sequence database to
generate a list of enzymes with high sequence similarity (>40%
identity) to the Streptococcus gordonii enzyme (SEQ ID NO:5). The
resulting list included 18 candidates.
TABLE-US-00002 Identity with MDP decarboxylase from Accession
Streptococcus number Microorganisms gordonii Genbank Streptococcus
oralis ATCC 35037 75 EFE56694.1 Leptotrichia goodfellowii F0264 61
EEY36155.1 Carnobacterium sp. AT7 40 EDP67928.1 Enterococcus
faecium TX1330 40 EEI60970.1 Staphylococcus aureus JH1 40
ABR51487.1 Streptococcus agalactiae NEM316 70 CAD47054.1
Streptococcus mutans UA159 71 AAN58642.1 Streptococcus uberis 0140J
71 CAR41735.1 Streptococcus infantarius subsp 71 EDT48420.1
infantarius ATCC BAA-102 (SEQ ID NO:7) Streptococcus gallolyticus
UCN34 71 CBI13757.1 (SEQ ID NO:11) Streptococcus dysgalactiae subsp
71 BAH81333.1 equisimilis GGS_124 Streptococcus sp. M143 76
EFA24040.1 (SEQ ID NO:13) Streptococcus salivarius SK126 74
EEK09252.1 (SEQ ID NO:15) Streptococcus suis 89/1591 40 EEF63672.1
(SEQ ID NO:14) Streptococcus parasanguinis ATCC 73 EFH19018.1 15912
Streptococcus sanguinis SK36 98 ABN43791.1 (SEQ ID NO:12)
Streptococcus sp. 2_1_36FAA 98 EEY81027.1 Streptococcus mitis B6 74
CBJ22986.1 (SEQ ID NO:10)
[0172] Sequences of MDP decarboxylase enzymes inferred from the
genomes of the above species as well as from the genome of S.
gordonii (SEQ ID NO:5) were generated by oligonucleotide
concatenation to fit the codon usage of E. coli. A stretch of 6
histidine codons was inserted after the methionine initiation codon
to provide an affinity tag for purification. The genes thus
synthesized were cloned in a pET25b expression vector (the vectors
were constructed by GENEART AG). After transformation of the E.
coli strain BL21(DE3), the proteins were produced according to the
protocol described in Example 1. The enzymes were then assayed
using the method described in Example 2, using Th. acidophilum MDP
decarboxylase (SEQ ID NO:2) instead of the P. torridus enzyme. This
screening procedure led to the identification of enzymes more
efficient for isobutene production than the S. gordonii enzyme (SEQ
ID NO:5) (FIG. 9), in particular MDP decarboxylases from S.
infantarius (SEQ ID NO:7), S. gallolyticus (SEQ ID NO:11), S. sp.
M143 (SEQ ID NO:13), S. salivarius (SEQ ID NO:15), S. suis (SEQ ID
NO:14), S. sanguinis (SEQ ID NO:12) and S. mitis (SEQ ID
NO:10).
Example 5
Characterisation of the Phosphotransferase Activity
[0173] The release of ADP that is associated with IBN production
from HIV was quantified using the pyruvate kinase/lactate
dehydrogenase coupled assay (FIG. 10). The MDP decarboxylases from
P. torridus (SEQ ID NO:1), Th. Acidophilum (SEQ ID NO:2), S.
infantarius (SEQ ID NO:7), S. mitis (SEQ ID NO:10) were evaluated
for their ability to phoshorylate HIV, releasing ADP.
[0174] The studied enzymatic reaction was carried out under the
following conditions at 40.degree. C.:
50 mM Tris-HCl pH 7,0
10 mM MgCl.sub.2
100 mM KCl
5 mM ATP
0.2 mM NADH
0.5 mM Phosphoenolpyruvate
[0175] 3 U/ml Lactate dehydrogenase 1.5 U/ml Pyruvate kinase
0-50 mM 3-Hydroxyisovalerate (HIV)
[0176] The pH was adjusted to 7,0.
[0177] Each assay was started by addition of particular enzyme (at
a concentration from 0.05 to 1 mg/ml) and the disappearance of NADH
was monitored by following the absorbance at 340 nM.
[0178] Assays with MDP decarboxylases from the P. torridus phylum
as well from the Streptococcus genus gave rise to a reproducible
increase in ADP production in the presence of HIV. FIG. 11 shows an
example of a Michaelis-Menten plot corresponding to the data
collected for P. torridus enzyme. The kinetic parameters are shown
in the following Table.
[0179] The enzymes from the P. torridus phylum displayed higher
phosphotransferase activities than those of the Streptococcus
genus.
Example 6
Isobutene Production from 3-Hydroxyisovalerate by Combining Two
Enzymes
[0180] The desired enzymatic reaction was carried out under the
following conditions:
50 mM Tris HCl pH 7,5
10 mM MgCl.sub.2
20 mM KCl
40 mM ATP
50 mM HIV
[0181] The pH was adjusted to 7,5
[0182] 100 .mu.g of MDP decarboxylase from Th. acidophilum (SEQ ID
NO:2) and 500 .mu.g of MDP decarboxylase from S. mitis (SEQ ID
NO:10) were added to 1 ml of reaction mixture. Control reactions
with only one of the two enzymes were run in parallel. The assays
were incubated without shaking at 37.degree. C. in a sealed vial
(Interchim).
[0183] The production of IBN was measured by analyzing aliquots
sampled over a 142 hour incubation period.
[0184] One ml of the gaseous phase was collected and injected into
a HP5890 gas chromatograph (HP) equipped with an FID detector and a
CP SilicaPlot column (Varian). Commercial isobutene was used as
reference.
[0185] The kinetics of isobutene production is shown in FIG. 12.
MDP decarboxylase from Th. acidophilum (SEQ ID NO:2) catalyzed the
production of isobutene from HIV. The addition of MDP decarboxylase
from S. mitis (SEQ ID NO:10) led to a 3-fold increase of isobutene
production after 142 h of incubation.
[0186] MDP decarboxylase from S. mitis (SEQ ID NO:10) alone
produced only small amounts of isobutene after 6 days of
incubation, indicating a low phosphotransferase activity.
TABLE-US-00003 k.sub.cat/ KM .times. 10.sup.-3, Organism K.sub.M,
mM k.sub.cat, sec.sup.-1 mM.sup.-1 sec.sup.-1 Thermoplasma
acidophilum 4.02 0.26 60 (SEQ ID NO:2) Picrophilus torridus 9.17
0.19 20 (SEQ ID NO:1) Streptococcus mitis 12.1 0.04 3 (SEQ ID
NO:10) Streptococcus infantarius 13.4 0.03 2 (SEQ ID NO:7)
[0187] Isobutene production can thus be increased by combining two
types of enzymes performing complementarily the two reaction
steps.
Example 7
Effect of ATP on Isobutene Production from 3-Phosphonoxyisovalerate
(PIV)
[0188] The compound 3-phosphonoxyisovalerate (PIV) was chemically
synthesized from 3-hydroxyisovalerate according to the scheme
depicted in FIG. 13 by SYNTHEVAL (France).
[0189] The assays of isobutene production were carried out under
the following conditions:
50 mM Tris-HCl pH 7,5
10 mM MgCl.sub.2
20 mM KCl
[0190] 0 mM ATP (assay N21 and N22) 10 mM ATP (assay N23 and N24)
25 mM 3-phosphonoxyisovalerate The pH was adjusted to 7.5
[0191] The reaction was initiated by addition of 2 mg of purified
MDP decarboxylase from S. mitis (SEQ ID NO:10) to 0.5 ml of
reaction mixture. Control reactions were run in the absence of
enzyme (assays No 1 and No 3).
[0192] The mixture was incubated without shaking at 37.degree. C.
for 26 h in a sealed vial of 2 ml (Interchim).
[0193] One ml of the gaseous phase was collected and injected into
a Varian 430-GC gas chromatograph equipped with an FID detector and
a CP SilicaPlot column (Varian). Commercial isobutene was used as
reference.
[0194] Addition of 10 mM ATP to the reaction mixture increased 120
fold isobutene production from 3-phosphonoxyisovalerate (PIV) (FIG.
14).
Example 8
Kinetic Parameters of Isobutene Production from
3-Phosphonoxyisovalerate (PIV)
[0195] The kinetic parameters of isobutene production were measured
under the following conditions:
50 mM Tris-HCl pH 7,5
10 mM MgCl.sub.2
50 mM KCl
40 mM ATP
[0196] 0-100 mM 3-phosphonoxyisovalerate The pH was adjusted to
7,5
[0197] The reaction was initiated by addition of 1 mg of purified
MDP decarboxylase from S. mitis (SEQ ID NO:10) to 0.5 ml of
reaction mixture. The mixture was then incubated without shaking at
37.degree. C. for 44 h in a sealed vial of 2 ml (Interchim).
[0198] One ml of the gaseous phase was collected and injected into
a Varian 430-GC gas chromatograph equipped with an FID detector and
a CP SilicaPlot column (Varian). Commercial isobutene was used as
reference.
[0199] The assays with MDP decarboxylase from S. mitis (SEQ ID
NO:10) showed a 160-400 fold increase in IBN production over the
background level (spontaneous decomposition of
3-phosphonoxyisovalerate) in the presence of ATP as co-factor (see
the following Table).
TABLE-US-00004 PIV concentration, Peak area, arbitrary units mM No
enzyme 2 mg/ml enzyme 25 164.9 26945.2 50 328.7 65720.4 75 561.5
239249.2 100 2078.7 339363.7
[0200] MDP decarboxylase from S. mitis (SEQ ID NO:10) was found to
have a K.sub.M higher than 60 mM and a k.sub.cat of at least
1.3.times.10.sup.-3 sec-1.
Sequence CWU 1
1
151324PRTPicrophilus torridus 1Met Glu Asn Tyr Asn Val Lys Thr Arg
Ala Phe Pro Thr Ile Gly Ile 1 5 10 15 Ile Leu Leu Gly Gly Ile Ser
Asp Lys Lys Asn Arg Ile Pro Leu His 20 25 30 Thr Thr Ala Gly Ile
Ala Tyr Thr Gly Ile Asn Asn Asp Val Tyr Thr 35 40 45 Glu Thr Lys
Leu Tyr Val Ser Lys Asp Glu Lys Cys Tyr Ile Asp Gly 50 55 60 Lys
Glu Ile Asp Leu Asn Ser Asp Arg Ser Pro Ser Lys Val Ile Asp 65 70
75 80 Lys Phe Lys His Glu Ile Leu Met Arg Val Asn Leu Asp Asp Glu
Asn 85 90 95 Asn Leu Ser Ile Asp Ser Arg Asn Phe Asn Ile Leu Ser
Gly Ser Ser 100 105 110 Asp Ser Gly Ala Ala Ala Leu Gly Glu Cys Ile
Glu Ser Ile Phe Glu 115 120 125 Tyr Asn Ile Asn Ile Phe Thr Phe Glu
Asn Asp Leu Gln Arg Ile Ser 130 135 140 Glu Ser Val Gly Arg Ser Leu
Tyr Gly Gly Leu Thr Val Asn Tyr Ala 145 150 155 160 Asn Gly Arg Glu
Ser Leu Thr Glu Pro Leu Leu Glu Pro Glu Ala Phe 165 170 175 Asn Asn
Phe Thr Ile Ile Gly Ala His Phe Asn Ile Asp Arg Lys Pro 180 185 190
Ser Asn Glu Ile His Glu Asn Ile Ile Lys His Glu Asn Tyr Arg Glu 195
200 205 Arg Ile Lys Ser Ala Glu Arg Lys Ala Lys Lys Leu Glu Glu Leu
Ser 210 215 220 Arg Asn Ala Asn Ile Lys Gly Ile Phe Glu Leu Ala Glu
Ser Asp Thr 225 230 235 240 Val Glu Tyr His Lys Met Leu His Asp Val
Gly Val Asp Ile Ile Asn 245 250 255 Asp Arg Met Glu Asn Leu Ile Glu
Arg Val Lys Glu Met Lys Asn Asn 260 265 270 Phe Trp Asn Ser Tyr Ile
Val Thr Gly Gly Pro Asn Val Phe Val Ile 275 280 285 Thr Glu Lys Lys
Asp Val Asp Lys Ala Met Glu Gly Leu Asn Asp Leu 290 295 300 Cys Asp
Asp Ile Arg Leu Leu Lys Val Ala Gly Lys Pro Gln Val Ile 305 310 315
320 Ser Lys Asn Phe 2318PRTThermoplasma acidophilum 2Met Thr Tyr
Arg Ser Ile Gly Ser Thr Ala Tyr Pro Thr Ile Gly Val 1 5 10 15 Val
Leu Leu Gly Gly Ile Ala Asn Pro Val Thr Arg Thr Pro Leu His 20 25
30 Thr Ser Ala Gly Ile Ala Tyr Ser Asp Ser Cys Gly Ser Ile Arg Ser
35 40 45 Glu Thr Arg Ile Tyr Ala Asp Glu Ala Thr His Ile Tyr Phe
Asn Gly 50 55 60 Thr Glu Ser Thr Asp Asp Asn Arg Ser Val Arg Arg
Val Leu Asp Arg 65 70 75 80 Tyr Ser Ser Val Phe Glu Glu Ala Phe Gly
Thr Lys Thr Val Ser Tyr 85 90 95 Ser Ser Gln Asn Phe Gly Ile Leu
Ser Gly Ser Ser Asp Ala Gly Ala 100 105 110 Ala Ser Ile Gly Ala Ala
Ile Leu Gly Leu Lys Pro Asp Leu Asp Pro 115 120 125 His Asp Val Glu
Asn Asp Leu Arg Ala Val Ser Glu Ser Ala Gly Arg 130 135 140 Ser Leu
Phe Gly Gly Leu Thr Ile Thr Trp Ser Asp Gly Phe His Ala 145 150 155
160 Tyr Thr Glu Lys Ile Leu Asp Pro Glu Ala Phe Ser Gly Tyr Ser Ile
165 170 175 Val Ala Phe Ala Phe Asp Tyr Gln Arg Asn Pro Ser Asp Val
Ile His 180 185 190 Gln Asn Ile Val Arg Ser Asp Leu Tyr Pro Ala Arg
Lys Lys His Ala 195 200 205 Asp Glu His Ala His Met Ile Lys Glu Tyr
Ala Lys Thr Asn Asp Ile 210 215 220 Lys Gly Ile Phe Asp Leu Ala Gln
Glu Asp Thr Glu Glu Tyr His Ser 225 230 235 240 Ile Leu Arg Gly Val
Gly Val Asn Val Ile Arg Glu Asn Met Gln Lys 245 250 255 Leu Ile Ser
Tyr Leu Lys Leu Ile Arg Lys Asp Tyr Trp Asn Ala Tyr 260 265 270 Ile
Val Thr Gly Gly Ser Asn Val Tyr Val Ala Val Glu Ser Glu Asn 275 280
285 Ala Asp Arg Leu Phe Ser Ile Glu Asn Thr Phe Gly Ser Lys Lys Lys
290 295 300 Met Leu Arg Ile Val Gly Gly Ala Trp His Arg Arg Pro Glu
305 310 315 3320PRTThermoplasma volcanium 3Met Ser Asn Ser Ser Ile
Thr Ser Val Ala Tyr Pro Thr Ile Gly Val 1 5 10 15 Val Leu Leu Gly
Gly Ile Ala Asn Glu Lys Thr Arg Thr Pro Leu His 20 25 30 Thr Ser
Ala Gly Ile Ala Tyr Thr Asp Ser Cys Gly Ser Ile Arg Thr 35 40 45
Glu Ser Thr Ile Tyr Gly Asp Ser Glu Met His Ile Tyr Phe Asn Gly 50
55 60 Thr Glu Ser Lys Asp Glu Asn Arg Ser Val Lys Ser Val Leu Glu
Arg 65 70 75 80 Tyr Arg Asn Glu Leu Gln Ser Phe Phe Gly Lys Lys Asp
Val Ser Tyr 85 90 95 Ser Ser Leu Asn Tyr Gly Ile Leu Ser Gly Ser
Ser Asp Ala Gly Ala 100 105 110 Ala Ser Ile Gly Ala Ile Leu Ser Phe
Ile Asp Lys Lys Asn Asp Ile 115 120 125 His Asp Ile Glu Asn Asp Ile
Arg Met Ile Ser Glu Ser Ala Gly Arg 130 135 140 Ser Leu His Gly Gly
Leu Thr Ile Thr Trp Ser Asp Gly Tyr Ser Ala 145 150 155 160 Tyr Thr
Glu Arg Val Leu Gly Pro Glu His Phe Asn Asn Tyr Ala Ile 165 170 175
Val Gly Phe Ser Phe Asp Tyr Pro Arg Asn Pro Ser Asp Thr Ile His 180
185 190 Gln Asn Ile Ile Lys Ser Lys Arg Tyr Lys Gln Arg Thr Ile Asp
Ala 195 200 205 Asp Glu His Ala His Glu Ile Lys Glu Met Ala Arg Thr
Asp Asp Ile 210 215 220 Glu Gly Ile Phe Glu Lys Ala Glu Glu Asp Thr
Glu Glu Tyr His Ser 225 230 235 240 Ile Leu Arg Glu Val Gly Val Leu
Val Ile Arg Glu Asn Met Gln Lys 245 250 255 Leu Ile Glu Phe Ile Lys
Ile Leu Arg Lys Glu Phe Trp Asn Ser Tyr 260 265 270 Ile Val Thr Gly
Gly Ser Asn Val Tyr Val Ile Val Arg Arg Asp Asp 275 280 285 Leu Glu
Arg Leu Ile His Ile Lys Asn Thr Phe Gly Ser Lys Pro Lys 290 295 300
Ile Leu Asn Val Ala Gly Pro Ala Trp Ile Lys Lys Val Glu Ser Asp 305
310 315 320 4322PRTFerroplasma acidarmanus fer1 4Met Glu Lys Tyr
Tyr Val Glu Val Lys Ala Tyr Pro Thr Ile Gly Ile 1 5 10 15 Leu Leu
Leu Gly Gly Val Ser Asp Asn Lys Lys Arg Leu Pro Arg His 20 25 30
Thr Thr Ala Gly Ile Ala Tyr Thr Gly Leu Asp Asp Asp Ile Tyr Val 35
40 45 Lys Thr Asp Leu Tyr Leu Ser Asn Gln Lys Ser Gly Ile Ile Asn
Gly 50 55 60 Lys Glu Val Ser Pro Asp Ser Pro Arg Ser Pro Phe Val
Val Ile Asp 65 70 75 80 Lys Tyr Arg His Glu Ile Leu Met Arg His Pro
Glu Tyr Ser Glu Val 85 90 95 Ser Phe Val Ser Glu Asn Lys Asn Val
Ile Ser Gly Ser Ser Asp Ala 100 105 110 Gly Ala Ala Ala Ile Gly Glu
Cys Ile Gln Ser Ile Phe Glu Tyr Asn 115 120 125 Ile Asn Ile Phe Asn
Phe Glu Asn Asp Leu Gln Gln Ile Ser Glu Ser 130 135 140 Ala Gly Arg
Ser Met Phe Gly Gly Phe Thr Ile Asn His Ala Asn Gly 145 150 155 160
Lys Glu Ser Leu Thr Asp Glu Ile Leu Gly Pro Glu Asp Phe Glu Asp 165
170 175 Phe Val Ile Val Ala Cys Lys Phe Ser Glu Asp Arg Lys Pro Ser
Asp 180 185 190 Thr Ile His Ser Asn Ile Ile Asn His Glu Lys Tyr Ala
Glu Arg Val 195 200 205 Lys Asn Ser Glu Leu Arg Ala Lys Glu Leu Glu
Lys Met Ala Asp Ser 210 215 220 Gly Asp Ile Lys Gly Ile Phe Glu Ala
Gly Glu Lys Asp Thr Gln Glu 225 230 235 240 Tyr His Ser Met Leu Arg
Glu Val Gly Val Ser Ile Ile Thr Asp Glu 245 250 255 Met Gln Arg Leu
Ile Glu Lys Val Glu Glu Leu Lys Ala Glu Phe Trp 260 265 270 Asn Ala
Tyr Ile Val Thr Gly Gly Thr Asn Val Phe Val Ala Val Glu 275 280 285
Arg Lys Asn Met Glu Lys Met Lys Asn Ala Ala Met Glu Phe Lys Cys 290
295 300 Thr Pro Val Tyr Leu Lys Val Ala Gly Lys Pro Asp Val Ile Ser
Lys 305 310 315 320 Asn Phe 5315PRTStreptococcus gordonii 5Met Asp
Arg Lys Pro Val Ser Val Lys Ser Tyr Ala Asn Ile Ala Ile 1 5 10 15
Val Lys Tyr Trp Gly Lys Lys Asp Ala Glu Lys Met Ile Pro Ser Thr 20
25 30 Ser Ser Ile Ser Leu Thr Leu Glu Asn Met Tyr Thr Glu Thr Gln
Leu 35 40 45 Ser Pro Leu Pro Ala Thr Ala Thr Gly Asp Glu Phe Tyr
Ile Asp Gly 50 55 60 Gln Leu Gln Ser Pro Ala Glu His Thr Lys Ile
Ser Lys Ile Ile Asp 65 70 75 80 Arg Phe Arg Ser Pro Glu Asp Gly Phe
Val Arg Val Asp Thr Ser Asn 85 90 95 Asn Met Pro Thr Ala Ala Gly
Leu Ser Ser Ser Ser Ser Gly Leu Ser 100 105 110 Ala Leu Val Lys Ala
Cys Asn Ala Tyr Phe Gln Thr Gly Tyr Gln Ala 115 120 125 Gln Glu Leu
Ala Gln Leu Ala Lys Phe Ala Ser Gly Ser Ser Ala Arg 130 135 140 Ser
Phe Phe Gly Pro Leu Ala Ala Trp Asp Lys Asp Ser Gly Ala Ile 145 150
155 160 Tyr Pro Val Lys Thr Asp Leu Lys Leu Ala Met Ile Met Leu Val
Leu 165 170 175 His Asp Glu Lys Lys Pro Ile Ser Ser Arg Asp Gly Met
Glu Leu Cys 180 185 190 Ala Lys Thr Ser Thr Ile Phe Pro Asp Trp Ile
Ala Gln Ser Ala Leu 195 200 205 Asp Tyr Gln Ala Met Leu Ala Tyr Leu
Arg Asp Asn Glu Phe Ala Lys 210 215 220 Val Gly Gln Leu Thr Glu Glu
Asn Ala Leu Arg Met His Ala Thr Thr 225 230 235 240 Glu Lys Ala Tyr
Pro Pro Phe Ser Tyr Leu Thr Glu Glu Ser Tyr Gln 245 250 255 Ala Met
Asp Ala Val Arg Lys Leu Arg Glu Gln Gly Glu Arg Cys Tyr 260 265 270
Phe Thr Met Asp Ala Gly Pro Asn Val Lys Val Leu Cys Leu Glu Glu 275
280 285 Asp Leu Asp His Leu Ala Ala Ile Leu Glu Lys Asp Tyr Arg Leu
Ile 290 295 300 Val Ser Lys Thr Lys Asp Leu Ser Asp Glu Ser 305 310
315 6315PRTStreptococcus gordonii str. Challis substr. CH1 6Met Asp
Arg Lys Pro Val Ser Val Lys Ser Tyr Ala Asn Ile Ala Ile 1 5 10 15
Val Lys Tyr Trp Gly Lys Lys Asp Ala Glu Lys Met Ile Pro Ser Thr 20
25 30 Ser Ser Ile Ser Leu Thr Leu Glu Asn Met Tyr Thr Glu Thr Gln
Leu 35 40 45 Ser Pro Leu Pro Asp Thr Ala Thr Gly Asp Glu Phe Tyr
Ile Asp Gly 50 55 60 Gln Leu Gln Ser Pro Ala Glu His Ala Lys Ile
Ser Lys Ile Ile Asp 65 70 75 80 Arg Phe Arg Ser Pro Glu Asp Gly Phe
Val Arg Val Asp Thr Ser Asn 85 90 95 Asn Met Pro Thr Ala Ala Gly
Leu Ser Ser Ser Ser Ser Gly Leu Ser 100 105 110 Ala Leu Val Lys Ala
Cys Asn Ala Tyr Phe Gln Thr Gly Tyr Gln Thr 115 120 125 Glu Glu Leu
Ala Gln Leu Ala Lys Phe Ala Ser Gly Ser Ser Ala Arg 130 135 140 Ser
Phe Phe Gly Pro Leu Ala Ala Trp Asp Lys Asp Ser Gly Ala Ile 145 150
155 160 Tyr Pro Val Lys Thr Asp Leu Lys Leu Ala Met Ile Met Leu Val
Leu 165 170 175 His Asp Glu Lys Lys Pro Ile Ser Ser Arg Asp Gly Met
Glu Leu Cys 180 185 190 Ala Lys Thr Ser Thr Ile Phe Pro Asp Trp Ile
Ala Gln Ser Ala Leu 195 200 205 Asp Tyr Gln Ala Met Leu Gly Tyr Leu
Gln Asp Asn Asp Phe Ala Lys 210 215 220 Val Gly Gln Leu Thr Glu Glu
Asn Ala Leu Arg Met His Ala Thr Thr 225 230 235 240 Glu Lys Ala Tyr
Pro Pro Phe Ser Tyr Leu Thr Glu Glu Ser Tyr Gln 245 250 255 Ala Met
Asp Ala Val Arg Lys Leu Arg Glu Gln Gly Glu Arg Cys Tyr 260 265 270
Phe Thr Met Asp Ala Gly Pro Asn Val Lys Val Leu Cys Leu Glu Glu 275
280 285 Asp Leu Asp His Leu Ala Ala Ile Phe Glu Lys Asp Tyr Arg Leu
Ile 290 295 300 Val Ser Lys Thr Lys Asp Leu Ser Asp Glu Ser 305 310
315 7311PRTStreptococcus infantarius subsp infantarius ATCC BAA-102
7Met Asp Arg Lys Ile Val Thr Val Lys Ser Tyr Ala Asn Ile Ala Ile 1
5 10 15 Ile Lys Tyr Trp Gly Lys Ala Asp Ala Ala Lys Met Ile Pro Ala
Thr 20 25 30 Ser Ser Ile Ser Leu Thr Leu Glu Asn Met Phe Thr Thr
Thr Ser Val 35 40 45 Ser Phe Leu Pro Asp Ser Ala Ser His Asp Glu
Phe Tyr Ile Asn Gly 50 55 60 Val Leu Gln Asp Asp Lys Glu His Ala
Lys Ile Ser Ala Ile Ile Asp 65 70 75 80 Gln Tyr Arg Gly Gln Arg Ser
Glu Tyr Val Lys Val Glu Thr Ser Asn 85 90 95 Asn Met Pro Thr Ala
Ala Gly Leu Ser Ser Ser Ser Ser Gly Leu Ser 100 105 110 Ala Leu Val
Lys Ala Cys Asn Glu Leu Phe Glu Thr Gly Leu Thr Arg 115 120 125 Ala
Glu Leu Ala Gln Lys Ala Lys Phe Ala Ser Gly Ser Ser Ser Arg 130 135
140 Ser Phe Phe Gly Pro Leu Ala Ala Trp Asp Lys Asp Ser Gly Glu Val
145 150 155 160 Tyr Pro Val Gln Thr Asp Leu Lys Leu Ala Met Ile Met
Leu Val Leu 165 170 175 Ser Asp Ser Lys Lys Ser Ile Ser Ser Arg Glu
Gly Met Lys Arg Cys 180 185 190 Val Glu Thr Ser Thr Thr Phe Ala Asp
Trp Val Lys Gln Ser Glu Gln 195 200 205 Asp Tyr Lys Asp Met Leu Gly
Tyr Leu Lys Asn Asn Asp Phe Glu Arg 210 215 220 Val Gly Glu Leu Thr
Glu Arg Asn Ala Leu Ala Met His Asp Thr Asn 225 230 235 240 Thr His
Ala Asn Pro Pro Phe Asn Tyr Leu Thr Glu Glu Ser Tyr Lys 245 250 255
Ala Met Glu Phe Val Lys Gln Leu Arg Ser Glu Gly Glu Lys Cys Tyr 260
265 270 Phe Thr Met Asp Ala Gly Pro Asn Val Lys Val Leu Cys Leu Glu
Glu 275 280 285 Asp Leu Glu Arg Leu Thr Lys Arg Phe Glu Glu Asn Tyr
Arg Val Ile 290 295 300 Val Ser Arg Thr Lys Glu Leu 305 310
8400PRTHomo sapiens 8Met Ala Ser Glu Lys Pro Leu Ala Ala Val Thr
Cys Thr Ala Pro Val 1 5 10 15 Asn Ile Ala Val Ile Lys Tyr Trp Gly
Lys Arg Asp Glu Glu Leu Val 20 25 30 Leu Pro Ile Asn Ser Ser Leu
Ser Val Thr Leu His Gln Asp Gln Leu 35
40 45 Lys Thr Thr Thr Thr Ala Val Ile Ser Lys Asp Phe Thr Glu Asp
Arg 50 55 60 Ile Trp Leu Asn Gly Arg Glu Glu Asp Val Gly Gln Pro
Arg Leu Gln 65 70 75 80 Ala Cys Leu Arg Glu Ile Arg Cys Leu Ala Arg
Lys Arg Arg Asn Ser 85 90 95 Arg Asp Gly Asp Pro Leu Pro Ser Ser
Leu Ser Cys Lys Val His Val 100 105 110 Ala Ser Val Asn Asn Phe Pro
Thr Ala Ala Gly Leu Ala Ser Ser Ala 115 120 125 Ala Gly Tyr Ala Cys
Leu Ala Tyr Thr Leu Ala Arg Val Tyr Gly Val 130 135 140 Glu Ser Asp
Leu Ser Glu Val Ala Arg Arg Gly Ser Gly Ser Ala Cys 145 150 155 160
Arg Ser Leu Tyr Gly Gly Phe Val Glu Trp Gln Met Gly Glu Gln Ala 165
170 175 Asp Gly Lys Asp Ser Ile Ala Arg Gln Val Ala Pro Glu Ser His
Trp 180 185 190 Pro Glu Leu Arg Val Leu Ile Leu Val Val Ser Ala Glu
Lys Lys Leu 195 200 205 Thr Gly Ser Thr Val Gly Met Arg Ala Ser Val
Glu Thr Ser Pro Leu 210 215 220 Leu Arg Phe Arg Ala Glu Ser Val Val
Pro Ala Arg Met Ala Glu Met 225 230 235 240 Ala Arg Cys Ile Arg Glu
Arg Asp Phe Pro Ser Phe Ala Gln Leu Thr 245 250 255 Met Lys Asp Ser
Asn Gln Phe His Ala Thr Cys Leu Asp Thr Phe Pro 260 265 270 Pro Ile
Ser Tyr Leu Asn Ala Ile Ser Trp Arg Ile Ile His Leu Val 275 280 285
His Arg Phe Asn Ala His His Gly Asp Thr Lys Val Ala Tyr Thr Phe 290
295 300 Asp Ala Gly Pro Asn Ala Val Ile Phe Thr Leu Asp Asp Thr Val
Ala 305 310 315 320 Glu Phe Val Ala Ala Val Trp His Gly Phe Pro Pro
Gly Ser Asn Gly 325 330 335 Asp Thr Phe Leu Lys Gly Leu Gln Val Arg
Pro Ala Pro Leu Ser Ala 340 345 350 Glu Leu Gln Ala Ala Leu Ala Met
Glu Pro Thr Pro Gly Gly Val Lys 355 360 365 Tyr Ile Ile Val Thr Gln
Val Gly Pro Gly Pro Gln Ile Leu Asp Asp 370 375 380 Pro Cys Ala His
Leu Leu Gly Pro Asp Gly Leu Pro Lys Pro Ala Ala 385 390 395 400
9319PRTLactobacillus delbrueckii 9Met Ser Lys Thr Ala Arg Ala His
Thr Asn Ile Ala Leu Ile Lys Tyr 1 5 10 15 Trp Gly Lys Lys Asp Ala
Lys Leu Arg Leu Pro Leu Met Ser Ser Leu 20 25 30 Ser Met Thr Leu
Asp Ala Phe Tyr Ser Asp Thr Lys Ile Ser Asp Ser 35 40 45 Glu Gln
Met Ser Phe Lys Leu Asn Gly Gln Ala Val Ser Gly Pro Ala 50 55 60
Ala Asp Arg Val Phe Ala Tyr Leu Arg Ala Met Gln Asp Arg Phe Gly 65
70 75 80 Val Lys Gly Asn Leu Ala Val Glu Ser Val Asn Gln Val Pro
Thr Ala 85 90 95 Ala Gly Leu Ala Ser Ser Ser Ser Ala Phe Ala Ala
Met Ala Ala Ala 100 105 110 Phe Ala Asp His Tyr Gln Leu Gly Val Asp
Arg Gln Glu Leu Ser Arg 115 120 125 Met Ala Arg Met Gly Ser Gly Ser
Ala Ser Arg Ser Val Phe Gly Gly 130 135 140 Phe Ser Val Trp Gln Lys
Gly Asp Ser Asp Gln Thr Ser Tyr Ala Tyr 145 150 155 160 Pro Leu Asp
Glu Glu Pro Asp Met Asp Leu Arg Leu Leu Ala Val Glu 165 170 175 Ile
Asn Asp Gln Glu Lys Lys Ile Ser Ser Thr Lys Gly Met Glu Met 180 185
190 Ser Lys Ser Ser Pro Phe Tyr Gln Val Trp Leu Asp Arg Asn Asp Ser
195 200 205 Glu Ile Lys Glu Met Glu Glu Ala Ile Lys Gln Ala Asp Phe
Ser Lys 210 215 220 Leu Gly Ser Leu Ala Glu Leu Asn Ala Ser Glu Met
His Thr Leu Thr 225 230 235 240 Phe Thr Ala Val Pro Gly Phe Thr Tyr
Phe Glu Pro Asn Thr Ile Lys 245 250 255 Ala Ile Lys Leu Val Gln Asp
Leu Arg Gln Gln Gly Leu Glu Cys Tyr 260 265 270 Tyr Thr Ile Asp Ala
Gly Pro Asn Val Lys Val Leu Cys Gln Gly Lys 275 280 285 Asn Ser Lys
Asp Ile Ile Asn Cys Phe Glu Ser Ser Phe Asp Arg Val 290 295 300 Lys
Ile Ile Glu Ala Gly Phe Gly Pro Gly Val Thr Leu Leu Asp 305 310 315
10317PRTStreptococcus mitis (strain B6) 10Met Asp Arg Glu Pro Val
Thr Val Arg Ser Tyr Ala Asn Ile Ala Ile 1 5 10 15 Ile Lys Tyr Trp
Gly Lys Lys Lys Glu Lys Glu Met Val Pro Ala Thr 20 25 30 Ser Ser
Ile Ser Leu Thr Leu Glu Asn Met Tyr Thr Glu Thr Thr Leu 35 40 45
Ser Ser Leu Pro Thr Asp Ala Thr Ala Asp Ala Phe Tyr Ile Asn Gly 50
55 60 Gln Leu Gln Asn Glu Ala Glu His Val Lys Met Ser Lys Ile Ile
Asp 65 70 75 80 Arg Tyr Arg Pro Asp Gly Asp Gly Phe Val Arg Ile Asp
Thr Gln Asn 85 90 95 Ser Met Pro Thr Ala Ala Gly Leu Ser Ser Ser
Ser Ser Gly Leu Ser 100 105 110 Ala Leu Val Lys Ala Cys Asn Ala Tyr
Phe Lys Leu Gly Leu Asn Arg 115 120 125 Ser Gln Leu Ala Gln Glu Ala
Lys Phe Ala Ser Gly Ser Ser Ser Arg 130 135 140 Ser Phe Tyr Gly Pro
Leu Gly Ala Trp Asp Lys Asp Ser Gly Glu Ile 145 150 155 160 Tyr Pro
Val Glu Thr Gly Leu Lys Leu Ala Met Ile Met Leu Val Leu 165 170 175
Glu Asp Lys Lys Lys Pro Ile Ser Ser Arg Asp Gly Met Lys Leu Cys 180
185 190 Val Glu Thr Ser Thr Thr Phe Asp Asp Trp Val Arg Gln Ser Glu
Lys 195 200 205 Asp Tyr Gln Asp Met Leu Val Tyr Leu Lys Ala Asn Asp
Phe Ala Lys 210 215 220 Val Gly Glu Leu Thr Glu Lys Asn Ala Leu Ala
Met His Ala Thr Thr 225 230 235 240 Lys Thr Ala Ser Pro Ala Phe Ser
Tyr Leu Thr Asp Ala Ser Tyr Glu 245 250 255 Ala Met Asp Phe Val Arg
Gln Leu Arg Glu Gln Gly Glu Ala Cys Tyr 260 265 270 Phe Thr Met Asp
Ala Gly Pro Asn Val Lys Val Leu Cys Gln Glu Lys 275 280 285 Asp Leu
Glu His Leu Ser Glu Ile Phe Gly Gln Arg Tyr Arg Leu Ile 290 295 300
Val Ser Lys Thr Lys Asp Leu Ser Gln Asp Gly Cys Cys 305 310 315
11316PRTStreptococcus gallolyticus UCN34 11Met Asp Arg Lys Ile Val
Thr Val Lys Ser Tyr Ala Asn Ile Ala Ile 1 5 10 15 Ile Lys Tyr Trp
Gly Lys Ala Asp Ala Val Lys Met Ile Pro Ala Thr 20 25 30 Ser Ser
Ile Ser Leu Thr Leu Glu Asn Met Phe Thr Thr Thr Thr Val 35 40 45
Ser Phe Leu Pro Gln Ser Val Gly His Asp Glu Phe Tyr Ile Asn Gly 50
55 60 Val Leu Gln Asp Glu Lys Glu His Ala Lys Ile Ser Ala Ile Ile
Asp 65 70 75 80 Gln Tyr Arg Gly Gly Arg Ser Glu Phe Val Lys Val Glu
Thr Ser Asn 85 90 95 Asn Met Pro Thr Ala Ala Gly Leu Ser Ser Ser
Ser Ser Gly Leu Ser 100 105 110 Ala Leu Val Lys Ala Cys Asn Glu Leu
Phe Glu Thr Gly Leu Asn Gln 115 120 125 Ser Glu Leu Ala Gln Lys Ala
Lys Phe Ala Ser Gly Ser Ser Ser Arg 130 135 140 Ser Phe Phe Gly Pro
Ile Ala Ala Trp Asp Lys Asp Ser Gly Asp Ile 145 150 155 160 Tyr Pro
Val Gln Thr Asp Leu Lys Leu Ala Met Ile Met Leu Val Leu 165 170 175
Ser Asp Ser Lys Lys Pro Ile Ser Ser Arg Glu Gly Met Lys Arg Cys 180
185 190 Ala Glu Thr Ser Thr Thr Phe Ala Asp Trp Val Lys Gln Ser Glu
Gln 195 200 205 Asp Tyr Lys Asp Met Leu Ala Tyr Leu Lys Ala Asn Asp
Phe Glu Lys 210 215 220 Val Gly Glu Leu Thr Glu Arg Asn Ala Leu Ala
Met His Asp Thr Asn 225 230 235 240 Thr His Ala Asn Pro Pro Phe Asn
Tyr Leu Thr Asp Glu Thr Tyr Ala 245 250 255 Ala Met Asp Phe Val Lys
Ser Leu Arg Thr Gln Gly Glu Lys Cys Tyr 260 265 270 Phe Thr Met Asp
Ala Gly Pro Asn Val Lys Val Leu Cys Leu Glu Glu 275 280 285 Asp Leu
Glu Cys Leu Thr Lys Arg Phe Glu Glu Asn Tyr Arg Val Ile 290 295 300
Ala Ser Arg Thr Lys Val Leu Pro Asp Glu Asn Asp 305 310 315
12315PRTStreptococcus sanguinis SK36 12Met Asp Arg Lys Pro Val Ser
Val Lys Ser Tyr Ala Asn Ile Ala Ile 1 5 10 15 Val Lys Tyr Trp Gly
Lys Lys Asp Ala Glu Lys Met Ile Pro Ser Thr 20 25 30 Ser Ser Ile
Ser Leu Thr Leu Glu Asn Met Tyr Thr Glu Thr Gln Leu 35 40 45 Ser
Pro Leu Pro Asp Thr Ala Thr Gly Asp Glu Phe Tyr Ile Asp Ser 50 55
60 Gln Leu Gln Ser Pro Ala Glu His Ala Lys Ile Ser Lys Ile Ile Asp
65 70 75 80 Arg Phe Arg Ser Pro Glu Asp Gly Phe Val Arg Val Asp Thr
Ser Asn 85 90 95 Asn Met Pro Thr Ala Ala Gly Leu Ser Ser Ser Ser
Ser Gly Leu Ser 100 105 110 Ala Leu Val Lys Ala Cys Asn Ala Tyr Phe
Gln Thr Gly Tyr Gln Thr 115 120 125 Gln Glu Leu Ala Gln Leu Ala Lys
Phe Ala Ser Gly Ser Ser Ala Arg 130 135 140 Ser Phe Phe Gly Pro Leu
Ala Ala Trp Asp Lys Asp Ser Gly Ala Ile 145 150 155 160 Tyr Pro Val
Lys Thr Asp Leu Lys Leu Ala Met Ile Met Leu Val Leu 165 170 175 His
Asp Glu Lys Lys Pro Ile Ser Ser Arg Asp Gly Met Glu Leu Cys 180 185
190 Ala Lys Thr Ser Thr Ile Phe Pro Asp Trp Ile Ala Gln Ser Ala Leu
195 200 205 Asp Tyr Lys Ala Met Leu Ser Tyr Leu Gln Asp Asn Asp Phe
Ala Lys 210 215 220 Val Gly Gln Leu Thr Glu Glu Asn Ala Leu Arg Met
His Ala Thr Thr 225 230 235 240 Glu Lys Ala Tyr Pro Pro Phe Ser Tyr
Leu Thr Glu Glu Ser Tyr Gln 245 250 255 Ala Met Asp Ala Val Arg Lys
Leu Arg Glu Gln Gly Glu Arg Cys Tyr 260 265 270 Phe Thr Met Asp Ala
Gly Pro Asn Val Lys Val Leu Cys Leu Glu Glu 275 280 285 Asp Leu Asp
His Leu Val Ala Ile Phe Glu Lys Asp Tyr Arg Leu Ile 290 295 300 Val
Ser Lys Thr Lys Asp Leu Ser Asp Glu Asp 305 310 315
13317PRTStreptococcus sp. M143 13Met Asp Arg Lys Pro Val Thr Val
Arg Ser Tyr Ala Asn Ile Ala Ile 1 5 10 15 Ile Lys Tyr Trp Gly Lys
Lys Lys Glu Lys Glu Met Val Pro Ala Thr 20 25 30 Ser Ser Ile Ser
Leu Thr Leu Glu Asn Met Tyr Thr Glu Thr Thr Leu 35 40 45 Ser Pro
Leu Pro Thr Asp Ala Thr Ala Asp Ala Phe Tyr Ile Asn Gly 50 55 60
Gln Leu Gln Ser Glu Ala Glu His Ala Lys Met Ser Lys Ile Ile Asp 65
70 75 80 Arg Tyr Arg Pro Ala Gly Glu Gly Phe Val Arg Ile Asp Thr
Gln Asn 85 90 95 Asn Met Pro Thr Ala Ala Gly Leu Ser Ser Ser Ser
Ser Gly Leu Ser 100 105 110 Ala Leu Val Lys Ala Cys Asn Ala Tyr Phe
Gln Leu Gly Leu Asn Arg 115 120 125 Ser Gln Leu Ala Gln Glu Ala Lys
Phe Ala Ser Gly Ser Ser Ser Arg 130 135 140 Ser Phe Tyr Gly Pro Leu
Gly Ala Trp Asp Lys Asp Ser Gly Glu Ile 145 150 155 160 Tyr Pro Val
Glu Thr Asp Leu Lys Leu Ala Met Ile Met Leu Val Leu 165 170 175 Glu
Asp Lys Lys Lys Pro Ile Ser Ser Arg Asp Gly Met Lys Leu Cys 180 185
190 Val Glu Thr Ser Thr Thr Phe Asp Asp Trp Val Arg Gln Ser Glu Lys
195 200 205 Asp Tyr Gln Asp Met Leu Leu Tyr Leu Lys Glu Asn Asp Phe
Ala Lys 210 215 220 Val Gly Glu Leu Thr Glu Lys Asn Ala Leu Ala Met
His Ala Thr Thr 225 230 235 240 Lys Thr Ala Ser Pro Ala Phe Ser Tyr
Leu Thr Asp Ala Ser Tyr Glu 245 250 255 Ala Met Asp Phe Val Arg Gln
Leu Arg Glu Gln Gly Glu Ser Cys Tyr 260 265 270 Phe Thr Met Asp Ala
Gly Pro Asn Val Lys Val Leu Cys Gln Glu Glu 275 280 285 Asp Leu Glu
His Leu Ser Glu Ile Phe Gly Gln Arg Tyr Arg Leu Ile 290 295 300 Val
Ser Lys Thr Lys Asp Leu Ser Gln Asp Asp Cys Cys 305 310 315
14341PRTStreptococcus suis 89/1591 14Met Thr Lys Gln Ile Gly Ile
Ala Arg Ala His Thr Asn Ile Ala Leu 1 5 10 15 Ile Lys Tyr Trp Gly
Lys Arg Asp Lys Glu Leu Phe Leu Pro Met Asn 20 25 30 Ser Ser Leu
Ser Leu Thr Leu Asp Ala Phe Tyr Thr Asp Thr Lys Val 35 40 45 Val
Phe Asp Pro Glu Leu Thr Ala Asp Glu Phe Tyr Leu Asn Gly Met 50 55
60 Leu Gln Lys Glu Lys Glu Ile Leu Lys Ile Ser Arg Phe Leu Asp Leu
65 70 75 80 Phe Cys Glu Tyr Ile Gly Glu Arg Ala Phe Ala Arg Val Glu
Ser Leu 85 90 95 Asn Phe Val Pro Thr Ala Ala Gly Leu Ala Ser Ser
Ala Ser Ala Phe 100 105 110 Ala Ala Leu Ala Leu Ala Thr Ala Thr Ala
Leu Asp Leu Asp Leu Ser 115 120 125 Pro Ala Thr Leu Ser Thr Leu Ala
Arg Arg Gly Ser Gly Ser Ser Thr 130 135 140 Arg Ser Leu Phe Gly Gly
Phe Val Glu Trp Asp Met Gly Thr Gly Ser 145 150 155 160 Glu Asp Ser
Met Ala His Pro Ile Asp Asp Ala Asp Trp Asp Ile Gly 165 170 175 Met
Val Val Leu Ala Val Asn Thr Gly Pro Lys Lys Ile Ala Ser Arg 180 185
190 Glu Gly Met Asp His Thr Val Ala Thr Ser Pro Phe Tyr Ser Ala Trp
195 200 205 Val Asp Thr Ala Lys Gln Asp Leu Ala Asp Ile Lys Ala Ala
Ile Ala 210 215 220 Gly Arg Asp Phe Glu Lys Leu Gly Gln Ile Thr Glu
His Asn Gly Met 225 230 235 240 Lys Met His Ala Thr Thr Leu Ser Ala
Asn Pro Pro Phe Thr Tyr Trp 245 250 255 Ser Ala Asp Ser Leu Val Ala
Gln Glu Ala Val Arg Gln Val Arg Glu 260 265 270 Ala Thr Gly Leu Ser
Ala Tyr Met Thr Met Asp Ala Gly Pro Asn Val 275 280 285 Lys Val Leu
Cys Arg Ala Ser Gln Met Asp Glu Leu Val Ala Glu Leu 290 295 300 Ala
Lys Val Phe Pro Arg Glu Lys Ile Ile Thr Ser Lys Pro Gly Pro 305 310
315 320 Ala Ala Tyr Val Leu Ser Glu Asp Glu Trp Gln Thr Ser Gln Ala
Ala 325 330
335 Phe Glu Lys Gly Leu 340 15314PRTStreptococcus salivarius SK126
15Met Asp Arg Lys Pro Val Ser Val Lys Ser Tyr Ala Asn Ile Ala Ile 1
5 10 15 Val Lys Tyr Trp Gly Lys Ala Asp Ala Glu Arg Met Ile Pro Ser
Thr 20 25 30 Ser Ser Ile Ser Leu Thr Leu Glu Asn Met Tyr Thr Glu
Thr Lys Leu 35 40 45 Ser Phe Leu Pro Glu Asp Ala Thr Gly Asp Val
Met Tyr Ile Asp Asp 50 55 60 Glu Leu Gln Gly Glu Lys Glu Thr Thr
Lys Ala Ser Lys Val Leu Asp 65 70 75 80 Leu Phe Arg Asn Asn Ser Asn
Gln His Val Lys Ile Glu Thr Trp Asn 85 90 95 Asn Met Pro Thr Ala
Ala Gly Leu Ser Ser Ser Ser Ser Gly Leu Ser 100 105 110 Ala Leu Val
Lys Ala Ala Asn Glu Leu Phe Gln Val Gly Lys Thr Gln 115 120 125 Ser
Glu Leu Ala Gln Ile Ala Lys Phe Ala Ser Gly Ser Ser Ser Arg 130 135
140 Ser Phe Phe Gly Pro Leu Ala Ala Trp Asp Lys Asp Ser Gly Glu Val
145 150 155 160 Tyr Pro Val Glu Thr Asp Leu Lys Leu Ala Met Ile Met
Leu Val Leu 165 170 175 Thr Asp Gln Lys Lys Pro Val Ser Ser Arg Asp
Gly Met Lys Leu Cys 180 185 190 Thr Glu Thr Ser Thr Ser Phe Pro Glu
Trp Ile Lys Gln Ser Glu Leu 195 200 205 Asp Tyr Lys Asp Met Leu Ala
Tyr Leu Lys Ala Asn Asp Phe Gln Ala 210 215 220 Val Gly Glu Leu Thr
Glu Ala Asn Ala Leu Arg Met His Gln Thr Thr 225 230 235 240 Ser Thr
Ala Asn Pro Pro Phe Ser Tyr Leu Thr Glu Ala Ser Tyr Gln 245 250 255
Ala Met Asp Lys Val Lys Ala Leu Arg Ala Ser Gly Glu Gln Cys Tyr 260
265 270 Phe Thr Met Asp Ala Gly Pro Asn Val Lys Val Leu Cys Leu Glu
Glu 275 280 285 Asp Leu Asp Arg Leu Ala Glu His Phe Arg Lys Asp Tyr
Gln Val Ile 290 295 300 Val Ser Arg Thr Lys Glu Leu Pro Asp Ala 305
310
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