U.S. patent application number 11/785365 was filed with the patent office on 2007-12-20 for method of producing recombinant aspergillus niger beta-glucosidase and an aroma spreading plant.
This patent application is currently assigned to Yissum Research Development Company of the Hebrew University of Jerusalem. Invention is credited to Ben-Ami Bravdo, Mara Dekel, Ira Marton, Oded Shoseyov, Wei Shu, Daniel L. Siegel.
Application Number | 20070292930 11/785365 |
Document ID | / |
Family ID | 23760395 |
Filed Date | 2007-12-20 |
United States Patent
Application |
20070292930 |
Kind Code |
A1 |
Shu; Wei ; et al. |
December 20, 2007 |
Method of producing recombinant Aspergillus niger beta-glucosidase
and an aroma spreading plant
Abstract
A polypeptide having .beta.-glucosidase enzymatic activity, a
polynucleotide encoding the polypeptide, a nucleic acid constructs
carrying the polynucleotide, transformed or infected cells, such as
yeast cells, and transgenic organisms expressing the polynucleotide
and various uses of the polypeptide, the polynucleotide, cells
and/or organisms, including, producing a recombinant polypeptide
having the .beta.-glucosidase enzymatic activity, increasing the
level of aroma compounds in alcoholic beverages, as well as other
fermentation products of plant material, hydrolyzing cellobiose and
thus increasing the level of fermentable glucose, increasing the
production of alcohol, such as ethanol from plant material,
increasing the aroma released from a plant or a plant product, and
hydrolysis or transglycosylation of glycosides.
Inventors: |
Shu; Wei; (Saskatoon,
CA) ; Siegel; Daniel L.; (Rechovot, IL) ;
Marton; Ira; (Rechovot, IL) ; Bravdo; Ben-Ami;
(Rehovot, IL) ; Dekel; Mara; (Rechovot, IL)
; Shoseyov; Oded; (Karmei Yosef, IL) |
Correspondence
Address: |
Martin D. Moynihan;PRTSI, Inc.
P.O. BOX 16446
Arlington
VA
22215
US
|
Assignee: |
Yissum Research Development Company
of the Hebrew University of Jerusalem
Jerusalem
IL
|
Family ID: |
23760395 |
Appl. No.: |
11/785365 |
Filed: |
April 17, 2007 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10130150 |
May 16, 2002 |
7223902 |
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PCT/IL00/00758 |
Nov 15, 2000 |
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11785365 |
Apr 17, 2007 |
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09443338 |
Nov 19, 1999 |
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10130150 |
May 16, 2002 |
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Current U.S.
Class: |
435/165 ;
435/161 |
Current CPC
Class: |
Y02E 50/16 20130101;
C12Y 302/01021 20130101; C12P 19/14 20130101; Y02E 50/10 20130101;
C12N 15/8243 20130101; Y02E 50/17 20130101; C12N 9/2445 20130101;
C12N 15/8242 20130101 |
Class at
Publication: |
435/165 ;
435/161 |
International
Class: |
C12P 7/10 20060101
C12P007/10; C12P 7/06 20060101 C12P007/06 |
Claims
1. A method of increasing a level of at least one fermentation
substance in a fermentation product, the method comprising the step
of fermenting a plant derived glucose containing fermentation
starting material by a yeast cell, said plant expressing a nucleic
acid construct comprising a polynucleotide encoding a polypeptide
having a .beta.-glucosidase catalytic activity and further encoding
a signal peptide being in frame with said polypeptide, said plant
having greater .beta.-glucosidase catalytic activity as compared to
.beta.-glucosidase catalytic activity of a plant not expressing
said nucleic acid construct, thereby increasing the level of the at
least one fermentation substance in the fermentation product.
2. The method of claim 1, wherein said polynucleotide further
encodes an endoplasmic reticulum retaining peptide being in frame
with said polypeptide.
3. The method of claim 1, wherein said signal peptide is an
apoplast and/or vacuole targeting signal peptide.
4. The method of claim 1, wherein said signal peptide is Cel1.
5. A method of increasing a level of at least one aroma substance
in a plant derived product, the method comprising the step of
incubating a glucose containing plant starting material with a
yeast cell, said plant expressing a nucleic acid construct
comprising a polynucleotide encoding a polypeptide having a
.beta.-glucosidase catalytic activity and further encoding a signal
peptide being in frame with said polypeptide, said plant having
greater .beta.-glucosidase catalytic activity as compared to
.beta.-glucosidase catalytic activity of a plant not expressing
said nucleic acid construct, thereby increasing the level of the at
least one aroma substance in the plant derived product.
6. The method of claim 5, wherein said polynucleotide further
encodes an endoplasmic reticulum retaining peptide being in frame
with said polypeptide.
7. The method of claim 5, wherein said signal peptide is an
apoplast and/or vacuole targeting signal peptide.
8. The method of claim 5, wherein said signal peptide is Cel1.
9. The method of claim 5, wherein said plant derived product is a
fermentation product.
10. A method of increasing a level of free glucose in a glucose
containing fermentation starting material, the method comprising
the step of fermenting the glucose containing fermentation starting
material by a cell expressing a nucleic acid construct comprising a
polynucleotide encoding a polypeptide having a .beta.-glucosidase
catalytic activity and further encoding a signal peptide being in
frame with said polypeptide, said cell having greater
.beta.-glucosidase catalytic activity as compared to
.beta.-glucosidase catalytic activity of a cell not expressing said
nucleic acid construct, thereby increasing the level of the free
glucose in the glucose containing fermentation starting
material.
11. The method of claim 10, wherein said polynucleotide further
encodes an endoplasmic reticulum retaining peptide being in frame
with said polypeptide.
12. The method of claim 10, wherein said signal peptide is an
apoplast and/or vacuole targeting signal peptide.
13. The method of claim 10, wherein said signal peptide is
Cel1.
14. A method of increasing a level of free glucose in a plant
derived glucose containing fermentation starting material, the
method comprising the step of fermenting the plant derived glucose
containing fermentation starting material by a cell, said plant
expressing a nucleic acid construct comprising a polynucleotide
encoding a polypeptide having a .beta.-glucosidase catalytic
activity and further encoding a signal peptide being in frame with
said polypeptide, said plant having greater .beta.-glucosidase
catalytic activity as compared to .beta.-glucosidase catalytic
activity of a plant not expressing said nucleic acid construct,
thereby increasing the level of the free glucose in the plant.
15. The method of claim 14, wherein said polynucleotide further
encodes an endoplasmic reticulum retaining peptide being in frame
with said polypeptide.
16. The method of claim 14, wherein said signal peptide is an
apoplast and/or vacuole targeting signal peptide.
17. The method of claim 14, wherein said signal peptide is
Cel1.
18. A method of producing an alcohol, the method comprising the
step of fermenting a glucose containing fermentation starting
material by a cell expressing a nucleic acid construct comprising a
polynucleotide encoding a polypeptide having a .beta.-glucosidase
catalytic activity and further encoding a signal peptide being in
frame with said polypeptide, said cell having greater
.beta.-glucosidase catalytic activity as compared to
.beta.-glucosidase catalytic activity of a cell not expressing said
nucleic acid construct and extracting the alcohol therefrom.
19. The method of claim 18, wherein said polynucleotide further
encodes an endoplasmic reticulum retaining peptide being in frame
with said polypeptide.
20. The method of claim 18, wherein said signal peptide is an
apoplast and/or vacuole targeting signal peptide.
21. The method of claim 18, wherein said signal peptide is
Cel1.
22. A method of producing an alcohol, the method comprising the
step of fermenting a plant derived glucose containing fermentation
starting material by a cell, said plant expressing a nucleic acid
construct comprising a polynucleotide encoding a polypeptide having
a .beta.-glucosidase catalytic activity and further encoding a
signal peptide being in frame with said polypeptide, said plant
having greater .beta.-glucosidase catalytic activity as compared to
.beta.-glucosidase catalytic activity of a plant not expressing
said nucleic acid construct, and extracting the alcohol
therefrom.
23. The method of claim 22, wherein said polynucleotide further
encodes an endoplasmic reticulum retaining peptide being in frame
with said polypeptide.
24. The method of claim 22, wherein said signal peptide is an
apoplast and/or vacuole targeting signal peptide.
25. The method of claim 22, wherein said signal peptide is
Cel1.
26. A method of producing a plant having increased release of
flavor and/or aroma compounds in-vivo, the method comprising the
step of expressing in the plant a nucleic acid construct comprising
a polynucleotide encoding a polypeptide having a .beta.-glucosidase
catalytic activity and further encoding an apoplast and/or vacuole
targeting signal peptide being in frame with said polypeptide and
wherein said polypeptide is secreted into the apoplast and/or
vacuole, said plant having greater .beta.-glucosidase catalytic
activity in the apoplast and/or vacuole as compared to
.beta.-glucosidase catalytic activity of the apoplast and/or
vacuole of a plant not expressing said nucleic acid construct,
thereby increasing in-vivo release of flavor and/or aroma compounds
from the plant.
27. The method of claim 26, wherein said signal peptide is
Cel1.
28. A method of producing a plant having increased release of
flavor and/or aroma compounds upon processing of the plant or
portion thereof, the method comprising the step of expressing in
the plant a nucleic acid construct comprising a polynucleotide
encoding a polypeptide having a .beta.-glucosidase catalytic
activity and further encoding a signal peptide and an endoplasmic
retention peptide being in frame with said polypeptide and wherein
said polypeptide accumulates in the endoplasmic reticulum, said
plant having greater .beta.-glucosidase catalytic activity in said
endoplasmic reticulum as compared to .beta.-glucosidase catalytic
activity of said endoplamic reticulum of a plant not expressing
said nucleic acid construct, thereby increasing release of flavor
and/or aroma compounds from the processing of said plant or portion
thereof, and wherein said processing comprises cell disruption and
decompartmentalization.
29. The method of claim 28, wherein said signal peptide is an
apoplast and/or vacuole targeting signal peptide.
30. The method of claim 28, wherein said signal peptide is
Cel1.
31. The method of claim 28, wherein said endoplasmic retention
peptide is selected from the group consisting of KDEL and HDEL.
Description
RELATED APPLICATIONS
[0001] This application is a continuation of pending U.S. patent
application Ser. No. 10/130,150 filed May 16, 2002, which is a U.S.
National Phase of PCT Patent Application No. PCT/IL00/00758 filed
Nov. 15, 2000, which is a continuation of U.S. patent application
Ser. No. 09/443,338 filed Nov. 19, 1999, now abandoned. The
contents of the above Applications are incorporated herein by
reference.
FIELD AND BACKGROUND OF THE INVENTION
[0002] The present invention relates to a polypeptide having
.beta.-glucosidase enzymatic activity, to a polynucleotide encoding
the polypeptide, to nucleic acid constructs carrying the
polynucleotide, to transformed or infected cells, such as yeast
cells, and organisms expressing the polynucleotide and to various
uses of the polypeptide, the polynucleotide, cells and/or
organisms, including, but not limited to, producing a recombinant
polypeptide having .beta.-glucosidase enzymatic activity,
increasing the level of aroma compounds in alcoholic beverages, as
well as other fermentation products of plant material, hydrolyzing
cellobiose and thus increasing the level of fermentable glucose, to
increase production of alcohol, such as ethanol from plant
material, increasing the aroma released from a plant or a plant
product, and hydrolysis or transglycosylation of glycosides.
[0003] Abbreviations used herein include: BGL1--Aspergillus niger
B1 .beta.-glucosidase; bgl1--a cDNA encoding same;
2FGlcF--2-deoxy-2-fluoro .beta.-glucosyl fluoride;
DNP--2,4-dinitrophenol; DNPGlc--2,4-dinitrophenyl
.beta.-D-glucopyranoside; pNP--p-nitrophenol; pNPGlc--p-nitrophenyl
.beta.-D-glucopyranoside;
MUGlc--4-methylumbeliferyl-.beta.-D-glucopyranoside; YNB--yeast
nitrogen base without amino acids; and
X-glu--5-bromo-4-chloro-3-indolyl .beta.-D-glucopyranoside.
[0004] .beta.-Glucosidases (EC 3.2.1.21; .beta.-D-glucoside
glucohydrolase) play a number of different important roles in
biology, including the degradation of cellulosic biomass by fungi
and bacteria, degradation of glycolipids in mammalian lysosomes and
the cleavage of glucosylated flavonoids in plants. These enzymes
are therefore of considerable industrial interest, not only as
constituents of cellulose-degrading systems, but also in the food
industry (2, 3).
[0005] Aspergillus species are known as a useful source of
.beta.-glucosidases (4-6), and Aspergillus niger is by far the most
efficient producer of .beta.-glucosidase among the microorganisms
investigated (4). Shoseyov et al. (7) have previously described a
.beta.-glucosidase from Aspergillus niger B1 (CMI CC 324626) which
is active at low pHs, as well as in the presence of high ethanol
concentrations. This enzyme effectively hydrolyzes flavor-compound
glycosides in certain low-pH products, such as wine and passion
fruit juice, thereby enhancing their flavor (8-12), and is
particularly attractive for use in the food industry, as A. niger
is considered non-toxic (3). In addition, .beta.-glucosidase was
found useful in enzymatic synthesis of glycosides (13-15). Other A.
niger .beta.-glucosidases have also been purified (16-18), however,
differences in their properties have been reported, including
ranges of molecular weights (116-137 kDa), isoelectric points (pI
values of 3.8-4) and pH optima (3.4-4.5). Indeed, at least two
.beta.-glucosidases, with distinct substrate specificities, have
been identified in commercial A. niger .beta.-glucosidase
preparations (19). Attempts to clear this confusion by cloning and
expression of a functional A. niger .alpha.-glucosidase gene in S.
cerevisiae has been previously reported (20), however the protein
was not characterized, and the sequence was not published.
[0006] Glycosidases have been assigned to families on the basis of
sequence similarities, there now being some 77 different such
families defined containing over 2,000 different enzymes (21, see
also the CAZy (Carbohydrate Active EnZymes) website, at the
Architecture of Fonction de Macromolecules Biologiques of the
Centre National de la Recherche Scientifique website. With the
exception of the glucosylceramidases (Family 30), all simple
.beta.-glucosidases belong to either Family 1 or 3. Family 1
contains enzymes from bacteria, plants and mammals, including also
6-phospho-glucosidases and thioglucosidases. Furthermore, most
Family 1 enzymes also have significant galactosidase activity.
Family 3 contains .beta.-glucosidases and hexosaminidases of
fungal, bacterial and plant origin. Enzymes of both families
hydrolyze their substrates with net retention of anomeric
configuration, presumably via a two-step, double-displacement
mechanism, involving two key active site carboxylic acid residues
(for reviews of mechanism, see 22-24). In the first step, one of
the carboxylic acids (the nucleophile) attacks at the substrate
anomeric center, while the other (the acid/base catalyst)
protonates the glycosidic oxygen, thereby assisting the departure
of the aglycone. This results in the formation of a covalent
.alpha.-glycosyl-enzyme intermediate. In a second step this
intermediate is hydrolyzed by general base-catalyzed attack of
water at the anomeric center of the glycosyl-enzyme, to release the
.beta.-glucose product and regenerate free enzyme. Both the
formation and the hydrolysis of this intermediate proceed via
transition states with substantial oxocarbenium ion character.
[0007] Given that Family 3 contains fungal enzymes of similar mass,
including those from other Aspergillus sp., it is likely that the
Aspergillus niger .beta.-glucosidase would be a member of this
family. Mechanistic information on this family is relatively
sparse: the best characterized being the glycosylated 170 kDa
.beta.-glucosidase from Aspergillus wentii. By labeling the active
site with conduritol B-epoxide, this enzyme was shown to carry out
hydrolysis, with net retention of anomeric configuration. This
study has demonstrated that the labeled aspartic acid residue was
the same as that derivatized by the slow substrate D-glucal (1,
25). Furthermore, it was shown that the 2-deoxyglucosyl-enzyme,
trapped by use of D-glucal, was kinetically identical to that
formed during the hydrolysis of
PNP-2-deoxy-.beta.-D-glucopyranoside (26). Further detailed kinetic
analysis of the enzyme was performed by Legler et al. (27),
including measurement of Hammett relationships, kinetic isotope
effects and studies of the binding of potent reversible inhibitors,
such as gluconolactone and nojirimycin.
[0008] While reducing the present invention to practice, the
.beta.-glucosidase protein was isolated from Aspergillus niger,
purified, cloned, sequenced, expressed in yeast host cells and its
enzymatic function characterized. In addition, the protein as well
as signal peptide fused thereto and optionally an endoplasmic
reticulum retaining peptide fused thereto were expressed in
transgenic plants and the release of aroma substances therefrom
following homogenization monitored. The enzyme encoded by the
isolated gene, as described above, is of known usefulness in plant
and/or plant products, as well as in biotechnological processes,
including the food industry. Several unexpected advantages were
uncovered, including, but not limited to, pH and temperature
stability of the .beta.-glucosidase from Aspergillus niger,
requirement for a signal peptide for obtaining catalytic activity
when expressed in plants. Advantage for an endoplasmic retaining
peptide or for a lack thereof when expressed in plants, depending
on the application.
SUMMARY OF THE INVENTION
[0009] According to one aspect of the present invention there is
provided an isolated nucleic acid comprising a genomic,
complementary or composite polynucleotide preferably being derived
from Aspergillus niger, encoding a polypeptide having a
.beta.-glucosidase catalytic activity and preferably further
encoding, in frame, a signal peptide and an endoplasmic reticulum
retaining peptide.
[0010] According to another aspect of the present invention there
is provided a recombinant protein comprising a polypeptide having a
.beta.-glucosidase catalytic activity, the polypeptide is
preferably derived from Aspergillus niger and it preferably fused
to a signal peptide and optionally also to an endoplasmic reticulum
retaining peptide.
[0011] According to yet another aspect of the present invention
there is provided a nucleic acid construct comprising the isolated
nucleic acid described herein.
[0012] According to still another aspect of the present invention
there is provided host cell or an organism, such as a plant,
comprising the nucleic acid or nucleic acid construct described
herein.
[0013] According to further features in preferred embodiments of
the invention described below, the polynucleotide is as set forth
in SEQ ID NOs:1, 3 or a portion thereof.
[0014] According to still further features in the described
preferred embodiments, the nucleic acid construct further
comprising at least one cis acting control element for regulating
expression of the polynucleotide.
[0015] According to still further features in the described
preferred embodiments, the host cell is selected from the group
consisting of a prokaryotic cell and a eukaryotic cell.
[0016] According to still further features in the described
preferred embodiments the prokaryotic cell is E. coli.
[0017] According to still further features in the described
preferred embodiments the eukaryotic cell is selected from the
group consisting of a yeast cell, a fungous cell, a plant cell and
an animal cell.
[0018] According to still further features in the described
preferred embodiments the polypeptide is as set forth in SEQ ID NO:
2 or a portion thereof having the .beta.-glucosidase catalytic
activity.
[0019] According to an additional aspect of the present invention
there is provided a method of producing recombinant
.beta.-glucosidase, the method comprising the step of introducing,
in an expressible form, a nucleic acid construct into a host cell,
the nucleic acid construct including a genomic, complementary or
composite polynucleotide preferably derived from Aspergillus niger,
encoding a polypeptide having a .beta.-glucosidase catalytic
activity and preferably further encoding, in frame, a signal
peptide and an endoplasmic reticulum retaining peptide.
[0020] According to further features in preferred embodiments of
the invention described below, the method further comprising the
step of extracting the polypeptide having the .beta.-glucosidase
catalytic activity.
[0021] According to yet an additional aspect of the present
invention there is provided a method of producing a recombinant
.beta.-glucosidase overexpressing cell, the method comprising the
step of introducing, in an overexpressible form, a nucleic acid
construct into a host cell, the nucleic acid construct including a
genomic, complementary or composite polynucleotide preferably
derived from Aspergillus niger, encoding a polypeptide having a
.beta.-glucosidase catalytic activity and preferably further
encoding, in frame, a signal peptide and an endoplasmic reticulum
retaining peptide.
[0022] According to still an additional aspect of the present
invention there is provided a method of increasing a level of at
least one fermentation substance in a fermentation product, the
method comprising the step of fermenting a glucose containing
fermentation starting material by a yeast cell overexpressing a
nucleic acid construct including a genomic, complementary or
composite polynucleotide being preferably derived from Aspergillus
niger, encoding a polypeptide having a .beta.-glucosidase catalytic
activity and preferably further encoding, in frame, a signal
peptide and an endoplasmic reticulum retaining peptide, thereby
increasing the level of the at least one fermentation substance in
the fermentation product.
[0023] According to a further aspect of the present invention there
is provided a method of increasing a level of at least one
fermentation substance in a fermentation product, the method
comprising the step of fermenting a plant derived glucose
containing fermentation starting material by a yeast cell, the
plant overexpressing a nucleic acid construct including a genomic,
complementary or composite polynucleotide preferably derived from
Aspergillus niger, encoding a polypeptide having a
.beta.-glucosidase catalytic activity and preferably further
encoding, in frame, a signal peptide and an endoplasmic reticulum
retaining peptide, thereby increasing the level of the at least one
fermentation substance in the fermentation product.
[0024] According to a further aspect of the present invention there
is provided a method of increasing a level of at least one aroma
substance in a plant derived product, the method comprising the
step of incubating a glucose containing plant starting material
with a yeast cell overexpressing a nucleic acid construct including
a genomic, complementary or composite polynucleotide preferably
derived from Aspergillus niger, encoding a polypeptide having a
.beta.-glucosidase catalytic activity and preferably further
encoding, in frame, a signal peptide and an endoplasmic reticulum
retaining peptide, thereby increasing the level of the at least one
aroma substance in the plant derived product.
[0025] According to yet a further aspect of the present invention
there is provided a method of increasing a level of at least one
aroma substance in a plant derived product, the method comprising
the step of incubating a glucose containing plant starting material
with a yeast cell, said plant overexpressing a nucleic acid
construct including a genomic, complementary or composite
polynucleotide preferably derived from Aspergillus niger, encoding
a polypeptide having a .beta.-glucosidase catalytic activity and
preferably further encoding, in frame, a signal peptide and an
endoplasmic reticulum retaining peptide, thereby increasing the
level of the at least one aroma substance in the plant derived
product.
[0026] According to still further features in the described
preferred embodiments the plant derived product is a fermentation
product, such as, but not limited to, an alcoholic beverage.
[0027] According to still a further aspect of the present invention
there is provided a method of increasing a level of free glucose in
a glucose containing fermentation starting material, the method
comprising the step of fermenting the glucose containing
fermentation starting material by a cell overexpressing a nucleic
acid construct including a genomic, complementary or composite
polynucleotide preferably derived from Aspergillus niger, encoding
a polypeptide having a .beta.-glucosidase catalytic activity and
preferably further encoding, in frame, a signal peptide and an
endoplasmic reticulum retaining peptide, thereby increasing the
level of the free glucose in the glucose containing fermentation
starting material.
[0028] According to another aspect of the present invention there
is provided a method of increasing a level of free glucose in a
plant derived glucose containing fermentation starting material,
the method comprising the step of fermenting the plant derived
glucose containing fermentation starting material by a cell, the
plant overexpressing a nucleic acid construct including a genomic,
complementary or composite polynucleotide preferably derived from
Aspergillus niger, encoding a polypeptide having a
.beta.-glucosidase catalytic activity and preferably further
encoding, in frame, a signal peptide and an endoplasmic reticulum
retaining peptide, thereby increasing the level of the free glucose
in the plant.
[0029] According to yet another aspect of the present invention
there is provided a method of increasing a level of free glucose in
a plant, the method comprising the step of overexpressing in the
plant a nucleic acid construct including a genomic, complementary
or composite polynucleotide preferably derived from Aspergillus
niger, encoding a polypeptide having a .beta.-glucosidase catalytic
activity and preferably further encoding, in frame, a signal
peptide and an endoplasmic reticulum retaining peptide, thereby
increasing the level of the free glucose in the plant.
[0030] According to still another aspect of the present invention
there is provided a method of producing an alcohol, the method
comprising the step of fermenting a glucose containing fermentation
starting material by a cell overexpressing a nucleic acid construct
including a genomic, complementary or composite polynucleotide
preferably derived from Aspergillus niger, encoding a polypeptide
having a .beta.-glucosidase catalytic activity and preferably
further encoding, in frame, a signal peptide and an endoplasmic
reticulum retaining peptide, and extracting the alcohol
therefrom.
[0031] According to an additional aspect of the present invention
there is provided a method of producing an alcohol, the method
comprising the step of fermenting a plant derived glucose
containing fermentation starting material by a cell, the plant
overexpressing a nucleic acid construct including a genomic,
complementary or composite polynucleotide preferably derived from
Aspergillus niger, encoding a polypeptide having a
.beta.-glucosidase catalytic activity and preferably further
encoding, in frame, a signal peptide and an endoplasmic reticulum
retaining peptide, and extracting the alcohol therefrom.
[0032] According to an additional aspect of the present invention
there is provided a method of producing an aroma spreading plant,
the method comprising the step of overexpressing in the plant a
nucleic acid construct including a genomic, complementary or
composite polynucleotide preferably derived from Aspergillus niger,
encoding a polypeptide having a .beta.-glucosidase catalytic
activity and preferably further encoding, in frame, a signal
peptide and an endoplasmic reticulum retaining peptide, thereby
increasing aroma spread from the plant.
[0033] According to further features in preferred embodiments of
the invention described below, overexpressing the nucleic acid
construct is performed in a tissue specific manner.
[0034] According to still further features in the described
preferred embodiments overexpressing the nucleic acid construct is
limited to at least one tissue selected from the group consisting
of flower, fruit, seed, root, stem, pollen and leaves.
[0035] The present invention successfully addresses the
shortcomings of the presently known configurations by providing a
polypeptide having .beta.-glucosidase enzymatic activity, a
polynucleotide encoding the polypeptide, a nucleic acid constructs
carrying the polynucleotide, transformed or infected cells, such as
yeast cells, and organisms expressing the polynucleotide and
various uses of the polypeptide, the polynucleotide, cells and/or
organisms, including, but not limited to, producing a recombinant
polypeptide having .beta.-glucosidase enzymatic activity,
increasing the level of aroma compounds in alcoholic beverages, as
well as other fermentation products of plant material, hydrolyzing
cellobiose and thus increasing the level of fermentable and/or free
glucose, to increase production of a fermentation product, such as
ethanol from plant material, increasing the aroma released from a
plant or a plant product, and hydrolysis or transglycosylation of
glycosides.
BRIEF DESCRIPTION OF THE DRAWINGS
[0036] The invention is herein described, by way of example only,
with reference to the accompanying drawings. With specific
reference now to the drawings in detail, it is stressed that the
particulars shown are by way of example and for purposes of
illustrative discussion of the preferred embodiments of the present
invention only, and are presented in the cause of providing what is
believed to be the most useful and readily understood description
of the principles and conceptual aspects of the invention. In this
regard, no attempt is made to show structural details of the
invention in more detail than is necessary for a fundamental
understanding of the invention, the description taken with the
drawings making apparent to those skilled in the art how the
several forms of the invention may be embodied in practice.
[0037] In the drawings:
[0038] FIGS. 1a-c demonstrate plasmid maps employed as expression
vectors for bgl1 cDNA. FIG. 1a--E. coli expression vector
containing bgl1 cDNA, inserted into the NcoI/BamHI sites of pET3d.
FIG. 1b--S. cerevisiae expression vector containing bgl1 cDNA,
inserted into the HindIII/BamHI sites of pYES2-bgl1 plasmid. FIG.
1c--P. pastoris expression vector containing bgl1 cDNA, inserted
into the EcoRI/BamHI sites of pHIL-S1.
[0039] FIGS. 2a-b demonstrates SDS-PAGE analysis of active protein
samples eluted from a MONO-Q.TM. (Amersham Biosciences Inc,
Piscatawy, N.J.) anion exchange column, stained with coomassie blue
(FIG. 2a), or .beta.-glucosidase zymogram (FIG. 2b) using MUGlc as
a substrate. Lanes (for both FIGS. 2a and 2b): 1--Electroeluted
band of BGL1 from preparative PAGE-SDS gel stabs; 2, 3, 4,
5--acetone precipitates from MONO-Q.TM. (Amersham Biosciences Inc,
Piscatawy, N.J.) anion exchange column separation of BGL1.
[0040] FIG. 3 demonstrates SDS-PAGE analysis of purified
.beta.-glucosidase by MONO-Q.TM. (Amersham Biosciences Inc,
Piscatawy, N.J.) anion exchange and RESOURCE-S.TM. (Amersham
Biosciences Inc, Piscatawy, N.J.) cation exchange columns. Lanes:
1--crude (27.5 .mu.g protein); 2--active fraction after MONO-Q.TM.
(Amersham Biosciences Inc, Piscatawy, N.J.) anion exchange (7 .mu.g
protein); and 3--active fraction after RESOURCE-S.TM. (Amersham
Biosciences Inc, Piscatawy, N.J.) cation exchange column (10 .mu.g
protein).
[0041] FIG. 4 demonstrates SDS-PAGE analysis of .beta.-glucosidase
deglycosylated by N-glycosidase-F. Lanes: 1--molecular weight
marker; 2--native .beta.-glucosidase; and 3--deglycosylated
protein.
[0042] FIG. 5a demonstrates the DNA (SEQ ID NO: 3) and amino acid
(SEQ ID NO: 2) sequences of bgl1. Amino acid sequences determined
by Edman degradation are underlined. DNA sequences of introns are
underlined. Signal peptide is indicated by italic letters.
[0043] FIG. 5b. demonstrates bgl1 gene organization. Exons (E1-7)
are indicated by filled boxes, introns by solid lines, restriction
sites and the stop codon by arrows.
[0044] FIG. 6a demonstrates a Western blot analysis of recombinant
BGL1 expressed in S. cerevisiae. Lanes: 1--native BGL1 (positive
control); 2--total protein extract of S. cerevisiae expressing
recombinant BGL1; 3--total protein extract of S. cerevisiae without
the bgl1 expression vector (negative control).
[0045] FIG. 6b demonstrates a Western blot analysis of recombinant
BGL1 secreted from P. pastoris. Lanes: 1--molecular weight marker;
2--medium supernatant of P. pastoris expressing recombinant BGL1;
3--medium supernatant of P. pastoris host without the vector
(negative control).
[0046] FIG. 7 demonstrates proton-NMR spectra, illustrating the
stereochemical course of pNPGlc hydrolysis by A. niger
.beta.-glucosidase. Spectra are for the anomeric proton region of
the substrate at different time intervals relative to addition of
the enzyme.
[0047] FIG. 8 demonstrates inactivation of recombinant BGL1 by
2FGlcF. Pure enzyme was incubated in the presence of various
concentrations of the inactivator, and residual enzyme activity was
determined at different time intervals. Residual activity is
presented, semilogarithmically, versus time, in the presence of the
indicated concentrations of inactivator.
[0048] FIG. 9 demonstrates reactivation of
2-deoxy-2-fluoroglucosyl-recombinant BGL 1 by linamarin. Activity
is plotted versus incubation time in the presence of the indicated
concentrations of linamarin.
[0049] FIG. 10 demonstrates the stability of recombinant A. niger
.beta.-glucosidase at various temperatures. Activity is calculated
as percent of a recombinant enzyme solution kept at 4.degree.
C.
[0050] FIGS. 11a-c show schematic depictions of expression
cassettes used for expression of A. niger .beta.-glucosidase in
tobacco plants. FIG. 11a--a cassette encoding BGL1 without a signal
peptide (see, SEQ ID NO:13 for the nucleotide sequence and SEQ ID
NO:14 for the amino acid sequence); FIG. 11b--a cassette encoding a
BGL1 fused to a Cel1 signal peptide for secretion into the apoplast
(see, SEQ ID NO:15 for the nucleotide sequence and SEQ ID NO:16 for
the amino acid sequence); and FIG. 11c--a cassette encoding a BGL1
fused to Cel1 signal peptide as in FIG. 11b and in addition to HDEL
(SEQ ID NO:17) ER-retaining peptide at the C-terminus for
accumulation in the ER (see, SEQ ID NO:18 for the nucleotide
sequence and SEQ ID NO:19 for the amino acid sequence).
[0051] FIG. 12 demonstrate PCR amplification results of bgl1 cDNA
indicating the presence of bgl1 cDNA in transgenic plants. CB10 and
CB11--transgenic plants transformed with bg1 and Cel1 signal
peptide without HDEL, SEQ ID NO:17 ER retaining peptide. CBT3, CBT8
and CBT15--different transgenic lines transformed with bgl1, Cel1
signal peptide and HDEL, SEQ ID NO:17. B1--a transgenic plants
transformed with bgl1. 1 kb-1 kb DNA marker. WT--wild type non
transgenic plant. pETB1-bgl1 plasmid DNA.
[0052] FIGS. 13a-b show Western blot analyses of transgenic plants
containing BGL1 without signal peptide (13a), and BGL1 with Cel1
signal peptide (13b), with and without HDEL, SEQ ID NO:17 ER
retaining peptide. An gluco-purified A. niger beta-glucosidase.
WT--nontransgenic control plant. B1, B15, B16, B20, B27, B33 and
B34--different transgenic lines transformed with bgl1. CBT1, CBT 3,
CBT 7 and CBT 8--different transgenic lines transformed with bgl1,
Cel1 signal peptide and HDEL, SEQ ID NO:17. CB10 and
CB12--transgenic plants transformed with bgl1 and Cel1 signal
peptide without HDEL, SEQ ID NO:17 ER retaining peptide.
[0053] FIG. 14 show activity gel analysis of transgenic tobacco
plant extracts in SDS-PAGE incubated with MUGlu. WT--non-transgenic
control plant. CB10 and CB11--two independent lines of transgenic
plants expressing BGL1 fused to Cel1 signal peptide (without HDEL,
SEQ ID NO:17). CBT3, CBT8 and CBT15--independent lines of
transgenic plants expressing BGL1 fused to Cel1 signal peptide at
the N terminus and HDEL, SEQ ID NO:17 ER retaining peptide at the C
terminus. B1 and B34--transgenic plant expressing BGL1 without
signal peptide or HDEL, SEQ ID NO:17 ER retaining peptide and which
were positive for BGL1 protein in Western blot analysis. An
Glu-control A. niger native beta-glucosidase.
[0054] FIG. 15 demonstrates level of BGL1 activity in different
transgenic plants. WT--non-transgenic control plant. B1 and
B21--transgenic plants expressing BGL1 without signal peptide or
HDEL, SEQ ID NO:17 ER retaining peptide and which were positive for
BGL1 in Western blot analysis. CBT8, CBT21, CBT0 and
CBT15--independent lines of transgenic plants expressing BGL1 fused
to Cel1 signal peptide at the N terminus and HDEL, SEQ ID NO:17 ER
retaining peptide at the C terminus. CB12, CB13, CB14 and
CB15--four independent lines of transgenic plants expressing BGL1
fused to Cel1 signal peptide (without HDEL, SEQ ID NO:17).
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0055] The present invention is of a polypeptide having
.beta.-glucosidase enzymatic activity, a polynucleotide encoding
the polypeptide, a nucleic acid constructs carrying the
polynucleotide, transformed or infected cells, such as yeast cells,
and organisms expressing the polynucleotide and various uses of the
polypeptide, the polynucleotide, cells and/or organisms, including,
but not limited to, producing a recombinant polypeptide having the
.beta.-glucosidase enzymatic activity, increasing the level of
aroma compounds in alcoholic beverages, as well as other
fermentation products of plant material, hydrolyzing cellobiose and
thus increasing the level of fermentable glucose, increasing the
production of alcohol, such as ethanol from plant material,
increasing the aroma released from a plant or a plant product, and
hydrolysis or transglycosylation of glycosides.
[0056] The principles and operation of the present invention may be
better understood with reference to the drawings and accompanying
descriptions.
[0057] Before explaining at least one embodiment of the invention
in detail, it is to be understood that the invention is not limited
in its application to the details of the components set forth in
the following description or exemplified in the examples that
follow. The invention is capable of other embodiments or of being
practiced or carried out in various ways. Also, it is to be
understood that the phraseology and terminology employed herein is
for the purpose of description and should not be regarded as
limiting.
[0058] According to one aspect of the present invention there is
provided an isolated nucleic acid comprising a genomic,
complementary or composite polynucleotide encoding a polypeptide
having a .beta.-glucosidase catalytic activity. Preferably the
polynucleotide is derived from Aspergillus niger, however other
sources are applicable. These include all isolated polynucleotides
encoding polypeptide having .beta.-glucosidase catalytic activity.
Such polynucleotides and polypeptides identified by their GenBank
Accession Nos. are listed in Table 1 below, all of which can be
used while implementing the present invention. TABLE-US-00001 TABLE
1 Accession numbers of cDNA and their encoded beta-glucosidases
(EC.3.2.1.21) Organism SWISS-PROT EMBL Acetobacter xylinus O24749
AB003689; AB010645 Agrobacterium sp. P12614 M19033; AAA22085.1
Agrobacterium tumefaciens P27034 M59852; AAA22082.1 Arabidopsis
thaliana O82772, O24433, O23656 AF082157; AF082158; AC009327;
U72153; U72155 AC020665; AC066691 Aspergillus aculeatus P48825
D64088, BAA10968.1 Aspergillus kawachi P87076 AB003470 Aspergillus
niger B1 AJ132386; CAB75696.1 Aspergillus niger AMS1 Q9P456
AF268911 Avena sativa Q38786, Q9ZP27 X78433; AF082991 Azospirillum
irakense AF090429; AAF21798.1 Bacillus circulans Q03506 M96979;
AAA22266.1 Bacillus sp. GL1 Q9ZNN7 AB009411; BAA36161.1; AB009410
Bacillus polymyxa P22073, P22505 M60210; M60211 Bacillus subtilis
P40740 Z34526; CAA84287.1 Bacillus subtilis P42403 D30762;
BAA06429.1 Bacteroides fragilis O31356 AF006658; AAB62870.1
Bifidobacterium breve P94248, O08487 D84489; D88311 Botryotinia
fuckeliana AJ130890; CAB61489.1 Brassica napus Q42618 X82577
Brassica nigra O24434 U72154 Butyrivibrio fibrisolvens P16084
M31120; AAA23008.1 Caldocellum saccharolyticum P10482 X12575;
CAA31087.1 Caldicellulosiruptor sp. 14B Q9ZEN0 AJ131346 Candida
wickerhamii Q12601 U13672 Cavia porcellus P97265 U50545
Cellulomonas biazotea O51843 AF005277; AAC38196.1 Cellulomonas fimi
Q46043 M94865 Cellvibrio gilvus P96316 D14068; BAA03152.1
Chryseobacterium O30713 AF015915 meningosepticum Clostridium
stercorarium O08331 Z94045 Clostridium thermocellum P26208 X60268;
CAA42814.1 Clostridium thermocellum P14002 X15644; CAA33665.1
Coccidioides immitis O14424 U87805; AF022893 Costus speciosus
Q42707 D83177 Dalbergia cochinchinensis Q9SPK3 AF163097
Dictyostelium discoideum Q23892 L21014 Digitalis lanata Q9ZPB6
AJ133406 Erwinia chrysanthemi Q46684 U08606; AAA80156.1 Erwinia
herbicola Q59437 X79911; CAA56282.1 Escherichia coli P33363 U15049;
AAB38487.1 scherichia coli K12/MG1655 E65074, Q46829 U28375;
AE000373 Glycine max AF000378; AAD09291.1 Hansenula anomala P06835
X02903; CAA26662.1 Homo sapiens AJ278964; CAC08178.1 Hordeum
vulgare Q40025 L41869 Humicola grisea var. thermoidea O93784
AB003109 Kluyveromyces marxianus P07337 X05918; CAA29353.1
Lactobacillus plantarum O86291 Y15954; AJ250202; CAB71149.1 Manihot
esculenta Q40283 X94986 Microbispora bispora P38645 M97265;
AAA25311.1 Nicotiana tabacum O82151 AB017502; BAA33065.1
Orpinomyces sp. PC-2 AF016864; AAD45834.1 Oryza sativa Q42975
U28047 Paenibacillus polymyxa P22073 M60210; AAA22263.1
Paenibacillus polymyxa P22505 M60211; AAA22264.1 Phaeosphaeria
avenaria AJ276675; CAB82861.1 Phanerochaete chrysosporium O74203
AF036872; AF036873 Pichia anomala (Candida P06835 X02903
pelliculosa) Pinus contorta AF072736; AAC696.1 Polygonum tinctorium
AB003089; BAA78708.1 Prunus avium Q43014 U39228 Prunus serotina
Q43073, Q40984 U50201; U26025 Prevotella albensis M384 AJ276021;
CAC07184.1 Prevotella ruminicola Q59716 U35425 Pyrococcus furiosus
Q51723 AF013169; U37557 Ruminococcus albus P15885 O66050 X15415;
CAA33461.1 U92808 Saccharomycopsis fibuligera P22506 M22475;
AAA34314.1 Saccharomycopsis fibuligera P22507 M22476; AAA34315.1
Saccharopolyspora erythraea O70021 Y14327 Salmonella typhimurium
Q56078 D86507; BAA13102.1 Schizophyllum commune P29091 M27313;
AAA33925.1 Schizosaccharomyces pombe AL355920; CAB91163.1 Secale
cereale AF293849; AAG00614.1 Septoria lycopersici Q99324 U24701;
U35462 Sorghum bicolor Q41290 U33817 Spodoptera frugiperda O61594
AF052729 Streptomyces coelicolor A3(2) AL121596; CAB56653.1
Streptomyces reticuli Q9X9R4 AJ009797 Streptomyces rochei A2 Q55000
X74291 Streptomyces sp. QM-B814 Q59976 Z29625 Thermoanaerobacter
brockii P96090, Q60026 Z56279; Z56279 Thermobifida fusca ER1
AF086819; AAF37727.1 Thermococcus sp. O08324 Z70242 Thermotoga
maritima Q08638 X74163; CAA52276.1 Thermotoga neapolitana O33843,
Q60038 Z97212; Z77856; CAB10165.1 Thermus sp. Z-1 Q9RA58 AB034947
Thermus thermophilus Q9X9D4 Y16753 Trichoderma reesei (Hypocrea
Q12715, U09580; AAA18473.1, Jecorina) O93785 AB003110 Trifolium
repens P26204 X56734; CAA40058.1 Trifolium repens P26205 X56733;
CAA40057.1 Tropaeolum majus O82074 AJ006501; CAA07070.1 Zea mays
P49235, Q41761 X74217, U25157; CAA52293.1 U33816, U44087, U44773
Unidentified bacterium Q60055 U12011
[0059] As used herein in the specification and in the claims
section that follows, the term "isolated" refers to a biological
component (such as a nucleic acid or protein or organelle) that has
been substantially separated or purified away from other biological
components in the cell of the organism in which the component
naturally occurs, i.e., other chromosomal and extra-chromosomal DNA
and RNA, proteins and organelles. Nucleic acids and proteins that
have been "isolated" include nucleic acids and proteins purified by
standard purification methods. The term also embraces nucleic acids
and proteins prepared by recombinant expression in a host cell as
well as chemically synthesized nucleic acids.
[0060] As used herein and in the claims section that follows the
terms and phrases "polynucleotide" and "polynucleotide sequence"
are used interchangeably and refer to a nucleotide sequence which
can be DNA or RNA of, for example, genomic or synthetic origin,
which may be single- or double-stranded, and which may represent
the sense or antisense strand. Similarly, the terms "polypeptide"
and "polypeptide sequence" are interchangeably used herein and
refer to an amino acid sequence of any length.
[0061] As used herein in the specification and in the claims
section that follows, the phrase "complementary polynucleotide
sequence" includes sequences, which originally result from reverse
transcription of messenger RNA using a reverse transcriptase or any
other RNA dependent DNA polymerase. Such sequences can be
subsequently amplified in vivo or in vitro using a DNA dependent
DNA polymerase.
[0062] As used herein in the specification and in the claims
section that follows, the phrase "genomic polynucleotide sequence"
includes sequences which originally derive from a chromosome and
reflect a contiguous portion of a chromosome.
[0063] As used herein in the specification and in the claims
section that follows, the phrase "composite polynucleotide
sequence" includes sequences which are at least partially
complementary and at least partially genomic. A composite sequence
can include some exonal sequences required to encode the
polypeptide having the .beta.-glucosidase catalytic activity, as
well as some intronic sequences interposing therebetween. The
intronic sequences can be of any source, including of other genes,
and typically will include conserved splicing signal sequences.
Such intronic sequences may further include cis acting expression
regulatory elements, as hereinbelow described.
[0064] As used herein in the specification and in the claims
section that follows, the phrase "having a .beta.-glucosidase
catalytic activity" refers to a polypeptide sequence, protein or
fragments thereof capable of serving as catalysts to a chemical
reaction involving hydrolysis of the O-glycosidic bond of
glucosides, the result of which is the release of a
.beta.-D-glucose residue(s), or an aglycon, in addition to the
.beta.-D-glucose residue. Specifically, hydrolysis by retaining
enzymes is performed while maintaining the .beta.-configuration of
the anomeric center of the carbohydrate. A wide specificity for
.beta.-glucosides exists, thus, some examples also hydrolyze one or
more of the following: .beta.-D-galactosides,
.alpha.-L-arabinosides, .beta.-D-xylosides, and
.beta.-D-fucosides.
[0065] As used herein the term "catalyst" refers to a substance
that accelerates a chemical reaction, but is not consumed or
changed permanently thereby.
[0066] As used herein the term "glucoside" refers to a compound of
at least two monomers, at least one of which is a glucose,
including a glycoside bond. Examples of glucosides include, but are
not limited to, glucose containing backbones, such as the diglucose
cellobiose, and the glucose polymer, cellulose.
[0067] According to preferred embodiments, the polynucleotide
according to this aspect of the present invention encodes a
polypeptide as set forth in SEQ ID NO:2 or a portion thereof which
retains .beta.-glucosidase catalytic activity.
[0068] Alternatively or additionally, the polynucleotide according
to this aspect of the present invention is as set forth in SEQ ID
NO:1, 3 or a portion thereof, the portion encodes a polypeptide
retaining .beta.-glucosidase catalytic activity.
[0069] In a broader aspect the polynucleotides according to the
present invention encode a polypeptide which is at least 75%, at
least 80%, at least 85%, at least 90%, at least 95% or more, say
95%-100% homologous to SEQ ID NO:2 as determined using the BestFit
software of the Wisconsin sequence analysis package, utilizing the
Smith and Waterman algorithm, where gap creation penalty equals 8
and gap extension penalty equals 2.
[0070] According to preferred embodiments, the polynucleotides
according to the broader aspect of the present invention encodes a
polypeptide as set forth in SEQ ID NOs:1 or 3 or a portion thereof
which retains activity.
[0071] Alternatively or additionally, the polynucleotides according
to this broader aspect of the present invention are hybridizable
with SEQ ID NOs: 1 or 3.
[0072] Hybridization for long nucleic acids (e.g., above 200 bp in
length) is effected according to preferred embodiments of the
present invention by stringent or moderate hybridization, wherein
stringent hybridization is effected by a hybridization solution
containing 10% dextrane sulfate, 1 M NaCl, 1% SDS and
5.times.10.sup.6 cpm .sup.32P labeled probe, at 65.degree. C., with
a final wash solution of 0.2.times.SSC and 0.1% SDS and final wash
at 65.degree. C.; whereas moderate hybridization is effected by a
hybridization solution containing 10% dextrane sulfate, 1 M NaCl,
1% SDS and 5.times.10.sup.6 cpm .sup.32p labeled probe, at
65.degree. C., with a final wash solution of 1.times.SSC and 0.1%
SDS and final wash at 50.degree. C.
[0073] Yet alternatively or additionally, the polynucleotides
according to this broad aspect of the present invention is
preferably at least 70%, at least 75%, at least 80%, at least 85%,
at least 90%, at least 95% or more, say 95%-100%, identical with
SEQ ID NOs: 1 or 3 as determined using the BestFit software of the
Wisconsin sequence analysis package, utilizing the Smith and
Waterman algorithm, where gap weight equals 50, length weight
equals 3, average match equals 10 and average mismatch equals
-9.
[0074] Thus, this broad aspect of the present invention encompasses
(i) polynucleotides as set forth in SEQ ID NOs:1 or 3; (ii)
fragments thereof; (iii) sequences hybridizable therewith; (iv)
sequences homologous thereto; (v) sequences encoding similar
polypeptides with different codon usage; (vi) altered sequences
characterized by mutations, such as deletion, insertion or
substitution of one or more nucleotides, either naturally occurring
or man induced, either randomly or in a targeted fashion.
[0075] According to another aspect of the present invention there
is provided a nucleic acid construct comprising the isolated
nucleic acid described herein.
[0076] According to a preferred embodiment, the nucleic acid
construct according to this aspect of the present invention further
comprising at least one cis acting control (regulatory) element for
regulating the expression of the isolated nucleic acid. Such cis
acting regulatory elements include, for example, promoters, which
are known to be sequence elements required for transcription, as
they serve to bind DNA dependent RNA polymerase, which transcribes
sequences present downstream thereof. Further details relating to
various regulatory elements are described hereinbelow.
[0077] While the isolated nucleic acid described herein is an
essential element of the invention, it is modular and can be used
in different contexts. The promoter of choice that is used in
conjunction with this invention is of secondary importance, and
will comprise any suitable promoter. It will be appreciated by one
skilled in the art, however, that it is necessary to make sure that
the transcription start site(s) will be located upstream of an open
reading frame. In a preferred embodiment of the present invention,
the promoter that is selected comprises an element that is active
in the particular host cells of interest. These elements may be
selected from transcriptional regulators that activate the
transcription of genes essential for the survival of these cells in
conditions of stress or starvation, including the heat shock
proteins.
[0078] A construct according to the present invention preferably
further includes an appropriate selectable marker. In a more
preferred embodiment according to the present invention the
construct further includes an origin of replication. In another
most preferred embodiment according to the present invention the
construct is a shuttle vector, which can propagate both in E. coli
(wherein the construct comprises an appropriate selectable marker
and origin of replication) and be compatible for propagation in
cells, or integration in the genome, of an organism of choice, such
as a plant. The construct according to this aspect of the present
invention can be, for example, a plasmid, a bacmid, a phagemid, a
cosmid, a phage, a virus or an artificial chromosome.
[0079] According to an additional aspect of the present invention
there is provided a recombinant protein comprising a polypeptide
having a .beta.-glucosidase catalytic activity. The polypeptide is
preferably derived from an Aspergillus niger and preferably
includes a signal peptide and optionally an endoplasmic reticulum
retaining peptide.
[0080] According to preferred embodiments, the polypeptide
according to this aspect of the present invention is as set forth
in SEQ ID NO:2 or a portion thereof which retains
.beta.-glucosidase catalytic activity.
[0081] SEQ ID NO:2 of A. niger .beta.-glucosidase is similar to the
amino acid sequence of the .beta.-glucosidase of A. kawachii.
However, while the former is highly stable at wide range of
temperatures and pH treatments, the latter is relatively unstable,
and thus has certain disadvantages, rendering its use for the
purpose of the present invention as is further detailed and
described hereinunder, unfeasible and/or much less attractive.
[0082] Recently, Iwashita and coworkers have published the sequence
of a .beta.-glucosidase (GenBank/EMBL AB003470) obtained from
Aspergillus kawachii strain: IF04308. Sequence comparison between
Aspergillus kawachii .beta.-glucosidase and A. niger
.beta.-glucosidase revealed that the two share 98% homology.
[0083] Enzymes of the two Aspergillus sp. contain seven cysteine
residues and identical number of glycosylation sites, while
differing in their degree of glycosylation (35).
[0084] The physical and kinetic properties of three
.beta.-glucosidases from Aspergillus kawachii were described (35),
and the three were shown to be products of the same gene, differing
solely by the degree of glycosylation. The three purified A.
kawachii .beta.-glucosidases were readily inactivated, even at
moderate pH and temperature conditions. In sharp distinction, while
examining the stability of the recombinant A. niger
.beta.-glucosidase according to the present invention under
conditions identical to those described by Iwashita et al. and as
described hereinbelow in the Examples section, revealed that the
enzyme is highly stable, retaining majority of the enzymatic
activity even after 1 hour incubation at 60.degree. C. (68%
activity, as defined by percent activity of an enzyme kept at
4.degree. C.).
[0085] Thus, despite the similarity between the A. kawachii and A.
niger .beta.-glucosidases, the A. niger enzyme unexpectedly
exhibits significantly higher thermal and pH stability.
[0086] According to yet another aspect of the present invention
there is provided a host cell comprising a nucleic acid construct
as described herein. The term "host cell" refers to a recipient of
a heterologous nucleic acid, which host cell can be either a
prokaryotic cell, such as E. coli, or a eukaryotic cell, such as a
yeast cell, a filamentous fungus cell, a plant cell or an animal
cell. Examples for a yeast cell include, but not limited to, Pichia
sp. such as P. pastoris, and Saccharomyces sp. such as S.
cervisiae.
[0087] As used herein and in the claims section which follows, the
term "heterologous" when used in context of a nucleic acid sequence
or a protein found within a plant, plant derived tissue or plant
cells, or alternatively, within a eukaryotic cell, such as yeast,
or a prokaryotic cell such as bacteria, refers to nucleic acid or
amino acid sequences typically not native to the plant, plant
derived tissue or plant cells, or alternatively, to the eukaryotic
cell, such as yeast, or the prokaryotic cell, such as bacteria.
Interchangeably, nucleic acid or amino acid sequences typically not
native to the plant, plant derived tissue or plant cells, or
alternatively, to the eukaryotic cell, such as yeast, or the
prokaryotic cell, such as bacteria, are referred to by "recombinant
nucleic acid" and "recombinant protein", respectively. Thus, a
recombinant nucleic acid is one that has a sequence that is not
naturally occurring or has a sequence that is made by an artificial
combination of two otherwise separated segments of sequence. This
artificial combination is often accomplished by chemical synthesis
or, more commonly, by the artificial manipulation of isolated
segments of nucleic acids, e.g., by genetic engineering
techniques.
[0088] As used herein in the specification and in the claims
section that follows, the term "eukaryotic cell" refers to a cell
containing a diploid genome through at least a portion of its life
cycle, having membrane-bound nucleus with chromosomes made of DNA,
with cell division involving a form of mitosis in which spindles
are involved. Possession of a eukaryote type of cell characterizes
the four kingdoms, Protoctista, Fungi, Plantae and Animalia.
[0089] As used herein in the specification and in the claims
section that follows, the term "prokaryotic cell" refers to various
bacteria and blue-green algae, characterized by the absence of the
nuclear organization, mitotic capacities and complex organelles
that typify the eukaryote superkingdom. Examples of prokaryotic
cell according to the present invention are bacteria, such as, but
not limited to, E. coli.
[0090] According to still another aspect of the present invention
there is provided an organism comprising a nucleic acid construct
as described herein, such as, but not limited to, a plant. Such an
organism is said to be transformed or virally infected.
[0091] As used herein the term "transformed" and its conjugations
such as transformation, transforming and transform, all relate to
the process of introducing heterologous nucleic acid sequences into
a cell or an organism, which nucleic acid sequences are
propagatable to the offspring. The term thus reads on, for example,
"genetically modified", "transgenic" and "transfected", which may
be used herein to further describe and/or claim the present
invention. The term relates both to introduction of a heterologous
nucleic acid sequence into the genome of an organism and/or into
the genome of a nucleic acid containing organelle thereof, such as
into a genome of chloroplast or a mitochondrion.
[0092] As used herein the phrase "viral infected" includes
infection by a virus carrying a heterologous nucleic acid sequence.
Such infection typically results in transient expression of the
nucleic acid sequence, which nucleic acid sequence is typically not
integrated into a genome and therefore not propagatable to
offspring, unless further infection of such offspring is
experienced.
[0093] There are various methods of introducing foreign genes into
both monocotyledonous and dicotyledenous plants (Potrykus, I.,
Annu. Rev. Plant. Physiol., Plant. Mol. Biol. (1991) 42:205-225;
Shimamoto et al., Nature (1989) 338:274-276). The principle methods
of causing stable integration of exogenous DNA into plant genomic
DNA include two main approaches:
[0094] (i) Agrobacterium-mediated gene transfer: Klee et al. (1987)
Annu. Rev. Plant Physiol. 38:467-486; Klee and Rogers in Cell
Culture and Somatic Cell Genetics of Plants, Vol. 6, Molecular
Biology of Plant Nuclear Genes, eds. Schell, J., and Vasil, L. K.,
Academic Publishers, San Diego, Calif. (1989) p. 2-25; Gatenby, in
Plant Biotechnology, eds. Kung, S, and Arntzen, C. J., Butterworth
Publishers, Boston, Mass. (1989) p. 93-112.
[0095] (ii) direct DNA uptake: Paszkowski et al., in Cell Culture
and Somatic Cell Genetics of Plants, Vol. 6, Molecular Biology of
Plant Nuclear Genes eds. Schell, J., and Vasil, L. K., Academic
Publishers, San Diego, Calif. (1989) p. 52-68; including methods
for direct uptake of DNA into protoplasts, Toriyama, K. et al.
(1988) Bio/Technology 6:1072-1074. DNA uptake induced by brief
electric shock of plant cells: Zhang et al. Plant Cell Rep. (1988)
7:379-384. From et al. Nature (1986) 319:791-793. DNA injection
into plant cells or tissues by particle bombardment, Klein et al.
Bio/Technology (1988) 6:559-563; McCabe et al. Bio/Technology
(1988) 6:923-926; Sanford, Physiol. Plant. (1990) 79:206-209; by
the use of micropipette systems: Neuhaus et al., Theor. Appl.
Genet. (1987) 75:30-36; Neuhaus and Spangenberg, Physiol. Plant.
(1990) 79:213-217; or by the direct incubation of DNA with
germinating pollen, DeWet et al. in Experimental Manipulation of
Ovule Tissue, eds. Chapman, G. P. and Mantell, S. H. and Daniels,
W. Longman, London, (1985) p. 197-209; and Ohta, Proc. Natl. Acad.
Sci. USA (1986) 83:715-719.
[0096] The Agrobacterium system includes the use of plasmid vectors
that contain defined DNA segments that integrate into the plant
genomic DNA. Methods of inoculation of the plant tissue vary
depending upon the plant species and the Agrobacterium delivery
system. A widely used approach is the leaf disc procedure, which
can be performed with any tissue explant that provides a good
source for initiation of whole plant differentiation. Horsch et al.
in Plant Molecular Biology Manual A5, Kluwer Academic Publishers,
Dordrecht (1988) p. 1-9. A supplementary approach employs the
Agrobacterium delivery system in combination with vacuum
infiltration. The Agrobacterium system is especially viable in the
creation of transgenic dicotyledenous plants.
[0097] There are various methods of direct DNA transfer into plant
cells. In electroporation, the protoplasts are briefly exposed to a
strong electric field. In microinjection, the DNA is mechanically
injected directly into the cells using very small micropipettes. In
microparticle bombardment, the DNA is adsorbed on microprojectiles
such as magnesium sulfate crystals or tungsten particles, and the
microprojectiles are physically accelerated into cells or plant
tissues.
[0098] Following transformation plant propagation is exercised. The
most common method of plant propagation is by seed. Regeneration by
seed propagation, however, has the deficiency that due to
heterozygosity there is a lack of uniformity in the crop, since
seeds are produced by plants according to the genetic variances
governed by Mendelian rules. Basically, each seed is genetically
different and each will grow with its own specific traits.
Therefore, it is preferred that the transformed plant be produced
such that the regenerated plant has the identical traits and
characteristics of the parent transgenic plant. Therefore, it is
preferred that the transformed plant be regenerated by
micropropagation, which provides a rapid, consistent reproduction
of the transformed plants.
[0099] Micropropagation is a process of growing new generation
plants from a single piece of tissue that has been excised from a
selected parent plant or cultivar. This process permits the mass
reproduction of plants having the preferred tissue expressing the
protein. The new generation plants, which are produced, are
genetically identical to, and have all of the characteristics of,
the original plant. Micropropagation allows mass production of
quality plant material in a short period of time and offers a rapid
multiplication of selected cultivars in the preservation of the
characteristics of the original transgenic or transformed plant.
The advantages of cloning plants are the speed of plant
multiplication and the quality and uniformity of plants
produced.
[0100] Micropropagation is a multi-stage procedure that requires
alteration of culture medium or growth conditions between stages.
Thus, the micropropagation process involves four basic stages:
Stage one, initial tissue culturing; stage two, tissue culture
multiplication; stage three, differentiation and plant formation;
and stage four, greenhouse culturing and hardening. During stage
one, initial tissue culturing, the tissue culture is established
and certified contaminant-free. During stage two, the initial
tissue culture is multiplied until a sufficient number of tissue
samples are produced to meet production goals. During stage three,
the tissue samples grown in stage two are divided and grown into
individual plantlets. At stage four, the transformed plantlets are
transferred to a greenhouse for hardening where the plants'
tolerance to light is gradually increased so that it can be grown
in the natural environment.
[0101] Sequences suitable for permitting integration of the
heterologous sequence into the plant genome are recommended. These
might include transposon sequences and the like for homologous
recombination as well as Ti sequences which permit random insertion
of a heterologous expression cassette into a plant genome.
[0102] Suitable prokaryote selectable markers include resistance
toward antibiotics such as ampicillin or tetracycline. Other DNA
sequences encoding additional functions may also be present in the
vector, as is known in the art.
[0103] The constructs of the subject invention will include an
expression cassette for expression of the protein of interest.
Usually, there will be only one expression cassette, although two
or more are feasible. The recombinant expression cassette will
contain in addition to the heterologous sequence one or more of the
following sequence elements, a promoter region, plant 5'
untranslated sequences which can include regulatory elements,
initiation codon depending upon whether or not the structural gene
comes equipped with one, and a transcription and translation
termination sequence. Unique restriction enzyme sites at the 5' and
3' ends of the cassette allow for easy insertion into a
pre-existing vector.
[0104] As used herein, the phrase "regulatory element" refers to a
nucleotide sequence which are typically included within an
expression cassette and function in regulating (i.e., enhancing or
depressing) the expression of a coding sequence therefrom. This
regulation can be effected either at the transcription or the
translation stages. Examples of regulatory elements include, but
are not limited to, enhancers, suppressers and transcription
terminators.
[0105] As used herein the term "promoter" refers to a nucleotide
sequence, which can direct gene expression in cells. Such a
promoter can be derived from a plant, a plant virus, or from any
other living organism including bacteria and animals.
[0106] A plant promoter can be a constitutive promoter, such as,
but not limited to, CaMV35S and CaMV19S promoters, FMV34S promoter,
sugarcane bacilliform badnavirus promoter, CsVMV promoter,
Arabidopsis ACT2/ACT8 actin promoter, Arabidopsis ubiquitin UBQ1
promoter, barley leaf thionin BTH6 promoter, and rice actin
promoter.
[0107] The promoter can alternatively be a tissue specific
promoter. Examples of plant tissue specific promoters include,
without being limited to, bean phaseolin storage protein promoter,
DLEC promoter, PHS.beta. promoter, zein stprotein promoter,
conglutin gamma promoter from soybean, AT2S1 gene promoter, ACT11
actin promoter from Arabidopsis, napA promoter from Brassica napus,
potato patatin gene promoter and the Tob promoter.
[0108] The promoter may also be a promoter which is active in a
specific developmental stage of a plant's life cycle, for example,
a promoter active in late embryogenesis, such as: the LEA promoter;
Endosperm-specific expression promoter (the seed storage prolamin
from rice is expressed in tobacco seed at the developmental stage
about 20 days after flowering) or the promoter controlling the
FbL2A gene during fiber wall synthesis stages.
[0109] In case of a tissue-specific promoter, it ensures that the
heterologous protein is expressed only in the desired tissue, for
example, only in the flower, the fruit, the root, the seed,
etc.
[0110] Both the tissue-specific and the non-specific promoters may
be constitutive, i.e., may cause continuous expression of the
heterologous protein.
[0111] The promoter may also be an inducible promoter, i.e., a
promoter which is activated by the presence of an inducing agent,
and only upon said activation, causes expression of the
heterologous protein. An inducing agent can be for example, light,
chemicals, drought, high salinity, osmotic shock, oxidant
conditions or in case of pathogenicity and include, without being
limited to, the light-inducible promoter derived from the pea rbcS
gene, the promoter from the alfalfa rbcS gene, the promoters DRE,
MYC and MYB active in drought; the promoters INT, INPS, prxEa, Ha
hsp17.7G4 and RD21 active in high salinity and osmotic stress, the
promoters hsr303J and str246C active in pathogenic stress, the
copper-controllable gene expression system and the
steroid-inducible gene system
[0112] Alternatively, an inducing agent may be an endogenous agent
which is normally present in only certain tissues of the plant, or
is produced only at certain time periods of the plant's life cycle,
such as ethylene or steroids. By using such an endogenous
tissue-specific inducing agent, it is possible to control the
expression from such inducible promoters only in those specific
tissues. By using an inducing agent produced only during a specific
period of the life cycle, it is possible to control the expression
from an inducible promoter to the specific phase in the life-cycle
in which the inducing agent is produced.
[0113] Bacterial and yeast derived promoters are well known in the
art.
[0114] Viruses are a unique class of infectious agents whose
distinctive features are their simple organization and their
mechanism of replication. In fact, a complete viral particle, or
virion, may be regarded mainly as a block of genetic material
(either DNA or RNA) capable of autonomous replication, surrounded
by a protein coat and sometimes by an additional membranous
envelope such as in the case of alpha viruses. The coat protects
the virus from the environment and serves as a vehicle for
transmission from one host cell to another.
[0115] Viruses that have been shown to be useful for the
transformation of plant hosts include CaV, TMV and BV.
Transformation of plants using plant viruses is described in U.S.
Pat. No. 4,855,237 (BGV), EP-A 67,553 (TMV), Japanese Published
Application No. 63-14693 (TMV), EPA 194,809 (BV), EPA 278,667 (BV);
and Gluzman, Y. et al., Communications in Molecular Biology: Viral
Vectors, Cold Spring Harbor Laboratory, New York, pp. 172-189
(1988). Pseudovirus particles for use in expressing foreign DNA in
many hosts, including plants, is described in WO 87/06261.
[0116] Construction of plant RNA viruses for the introduction and
expression of non-viral foreign genes in plants is demonstrated by
the above references as well as by Dawson, W. O. et al., Virology
(1989) 172:285-292; Takamatsu et al. EMBO J. (1987) 6:307-311;
French et al. Science (1986) 231:1294-1297; and Takamatsu et al.
FEBS Letters (1990) 269:73-76.
[0117] When the virus is a DNA virus, the constructions can be made
to the virus itself. Alternatively, the virus can first be cloned
into a bacterial plasmid for ease of constructing the desired viral
vector with the foreign DNA. The virus n then be excised from the
plasmid. If the virus is a DNA virus, a bacterial origin of
replication can be attached to the viral DNA, which is then
replicated by the bacteria. Transcription and translation of this
DNA will produce the coat protein which will encapsidate the viral
DNA. If the virus is an RNA virus, the virus is generally cloned as
a cDNA and inserted into a plasmid. The plasmid is then used to
make all of the constructions. The RNA virus is then produced by
transcribing the viral sequence of the plasmid and translation of
the viral genes to produce the coat protein(s) which encapsidate
the viral RNA.
[0118] Construction of plant RNA viruses for the introduction and
expression of non-viral foreign genes in plants is demonstrated by
the above references as wellasin U.S. Pat. No. 5,316,931.
[0119] In one embodiment, a plant viral nucleic acid is provided in
which the native coat protein coding sequence has been deleted from
a viral nucleic acid, a non-native plant viral coat protein coding
sequence and a non promoter, preferably the subgenomic promoter of
the non-native coat protein coding sequence, capable of expression
in the plant host, packaging of the recombinant plant viral nucleic
acid, and ensuring a systemic infection of the host by the
recombinant plant viral nucleic acid, has been inserted.
Alternatively, the coat protein gene may be inactivated by
insertion of the non-native nucleic acid sequence within it, such
that a protein is produced. The recombinant plant viral nucleic
acid may contain one or more additional non-native subgenomic
promoters. Each non-native subgenomic promoter is capable of
transcribing or expressing adjacent genes or nucleic acid sequences
in the plant host and incapable of recombination with each other
and with native subgenomic promoters. Non-native (foreign) nucleic
acid sequences may be inserted adjacent the native plant viral
subgenomic promoter or the native and a non-native plant viral
subgenomic promoters if more than one nucleic acid sequence is
included. The non-native nucleic acid sequences are transcribed or
expressed in the host plant under control of the subgenomic
promoter to produce the desired products.
[0120] In a second embodiment, a recombinant plant viral nucleic
acid is provided as in the first embodiment except that the native
coat protein coding sequence is placed adjacent one of the
non-native coat protein subgenomic promoters instead of a
non-native coat protein coding sequence.
[0121] In a third embodiment, a recombinant plant viral nucleic
acid is provided in which the native coat protein gene is adjacent
its subgenomic promoter and one or more non-native subgenomic
promoters have been inserted into the viral nucleic acid. The
inserted non-native subgenomic promoters are capable of
transcribing or expressing adjacent genes in a plant host and are
incapable of recombination with each other and with native
subgenomic promoters. Non-native nucleic acid sequences may be
inserted adjacent the non-native subgenomic plant viral promoters
such that said sequences are transcribed or expressed in the host
plant under control of the subgenomic promoters to produce the
desired product.
[0122] In a fourth embodiment, a recombinant plant viral nucleic
acid is provided as in the third embodiment except that the native
coat protein coding sequence is replaced by a non-native coat
protein coding sequence.
[0123] The viral vectors are encapsidated by the coat proteins
encoded by the recombinant plant viral nucleic acid to produce a
recombinant plant virus. The recombinant plant viral nucleic acid
or recombinant plant virus is used to infect appropriate host
plants. The recombinant plant viral nucleic acid is capable of
replication in the host, systemic spread in the host, and
transcription or expression of foreign gene(s) in the host to
produce the desired protein.
[0124] In many instances it is desired to target the expression of
a recombinant protein. Such targeting can be into a cellular
organelle or outside of the cell. This can be effected, as is well
known in the art, by appropriate signal peptides, which are fused
to the polypeptide to be targeted, typically at the N terminus.
[0125] Thus, as used herein and in the claims section which
follows, the phrase "signal peptide" refers to a stretch of amino
acids which is effective in targeting a protein expressed in a cell
into a target location. Different signal peptides, which are known
in the art, are effective in secreting a protein from bacteria,
yeast, plant and animal cells.
[0126] It should be noted in this respect that signal peptides
serve the function of translocation of produced protein across the
endoplasmic reticulum membrane. Similarly, transmembrane segments
halt translocation and provide anchoring of the protein to the
plasma membrane, see, Johnson et al. The Plant Cell (1990)
2:525-532; Sauer et al. EMBO J. (1990) 9:3045-3050; Mueckler et al.
Science (1985) 229:941-945. Mitochondrial, nuclear, chloroplast, or
vacuolar signals target expressed protein correctly into the
corresponding organelle through the secretory pathway, see, Von
Heijne, Eur. J. Biochem. (1983) 133:17-21; Yon Heijne, J. Mol.
Biol. (1986) 189:239-242; Iturriaga et al. The Plant Cell (1989)
1:381-390; McKnight et al., Nucl. Acid Res. (1990) 18:4939-4943;
Matsuoka and Nakamura, Proc. Natl. Acad. Sci. USA (1991)
88:834-838. A recent book by Cunningham and Porter (Recombinant
proteins from plants, Eds. C. Cunningham and A. J. R. Porter, 1998
Humana Press Totowa, N.J.) describe methods for the production of
recombinant proteins in plants and methods for targeting the
proteins to different compartments in the plant cell. In
particular, two chapters therein (14 and 15) describe different
methods to introduce targeting sequences that results in
accumulation of recombinant proteins in compartments such as ER,
vacuole, plastid, nucleus and cytoplasm. The book by Cunningham and
Porter is incorporated herein by reference. Presently, the
preferred site of accumulation of the fusion protein according to
the present invention is the ER using signal peptide such as Cel 1
or the rice amylase signal peptide at the N-terminus and an ER
retaining peptide (HDEL, SEQ ID NO:17; or KDEL, SEQ ID NO:24) at
the C-terminus.
[0127] According to an additional aspect of the present invention
there is provided a method of producing recombinant
.beta.-glucosidase. The method according to this aspect of the
present invention is effected by introducing, in an expressible or
overexpressible form, a nucleic acid construct into a host cell.
The nucleic acid construct includes a genomic, complementary or
composite polynucleotide preferably derived from Aspergillus niger
and encoding a polypeptide having a .beta.-glucosidase catalytic
activity. The polynucleotide preferably further encodes a signal
peptide in frame with the polypeptide. Still preferably, the
polynucleotide further encodes an endoplasmic reticulum retaining
peptide in frame with the polypeptide.
[0128] As used herein the term "introducing" refers both to
transforming and to virally infecting, as these terms are further
defined hereinabove. As used herein the terms "expressible form"
and "overexpressible form" refers to a recombinant form which
includes the required regulatory elements to effect expression or
over expression of a coding region, all as is further detailed
hereinabove.
[0129] According to a preferred embodiment of this aspect of the
present invention, after sufficient expression has been detected,
the polypeptide having the .beta.-glucosidase catalytic activity is
extracted from the expressing host cell.
[0130] Thus host cells, expressing the polypeptide according to the
present invention, provide an immediate, easy and indefinite source
of the polypeptide.
[0131] Any number of well-known liquid or solid culture media may
be used for appropriately culturing host cells of the present
invention, although growth on liquid media is preferred as the
secretion of the polypeptide into the media results in
simplification of polypeptide recovery. As is further detailed
hereinabove, such secretion can be effected by the incorporation of
a suitable signal peptide. The .beta.-glucosidase may be isolated
or separated or purified from host cell preparations using
techniques well known in the art, such as, but not limited to,
centrifugation filtration, chromatography, electrophoresis and
dialysis. Further concentration and/or purification of the
.beta.-glucosidase may be effected by use of conventional
techniques, including, but not limited to, ultrafiltration, further
dialysis, ion-exchange chromatography, HPLC, size-exclusion
chromatography, cellobiose-sepharose affinity chromatography, and
electrophoresis, such as polyacrylamide-gel-electrophoresis (PAGE).
Using these techniques, .beta.-glucosidase may be recovered in pure
or substantially pure form.
[0132] According to an additional aspect of the present invention
there is provided a method of increasing a level of at least one
fermentation substance in a fermentation product. The method
according to this aspect of the present invention is effected by
fermenting a glucose containing fermentation starting material by a
yeast cell overexpressing a nucleic acid construct which includes a
genomic, complementary or composite polynucleotide preferably
derived from Aspergillus niger and which encodes a polypeptide
having a .beta.-glucosidase catalytic activity, thereby increasing
the level of the at least one fermentation substance in the
fermentation product. The polynucleotide preferably further encodes
a signal peptide in frame with the polypeptide. Still preferably,
the polynucleotide further encodes an endoplasmic reticulum
retaining peptide in frame with the polypeptide.
[0133] According an alternative aspect of the present invention
there is provided a method of increasing a level of at least one
fermentation substance in a fermentation product. The method
according to this aspect of the present invention is effected by
fermenting a plant derived glucose containing fermentation starting
material by a yeast cell, the plant overexpressing a nucleic acid
construct which includes a genomic, complementary or composite
polynucleotide preferably derived from Aspergillus niger and which
encodes a polypeptide having a .beta.-glucosidase catalytic
activity, thereby increasing the level of the at least one
fermentation substance in the fermentation product. The
polynucleotide preferably further encodes a signal peptide in frame
with the polypeptide. Still preferably, the polynucleotide further
encodes an endoplasmic reticulum retaining peptide in frame with
the polypeptide.
[0134] As used herein in the specification and in the claims
section that follows, the term "fermentation" refers to a chemical
change induced in a complex organic compound by the action of an
enzyme, whereby the substance is split into simpler compounds.
Specifically, the term "fermentation" includes the anaerobic
dissimilation of substrates with the production of energy and
reduced compounds, the final products thereof are organic acids,
alcohols, such as ethanol, isopropanol, butanol, etc., and
CO.sub.2. Such products, are typically secreted and each of which
is referred to herein as a "fermentation substance", i.e., any
known fermentation resultant of either microbial or yeast
fermentation.
[0135] As used herein in the specification and in the claims
section that follows, the phrase "fermentation product" refers to
the resultant material of a fermentation process. Examples include,
but are not limited to, alcohol containing fermentation medium and
alcoholic beverages, such a, but not limited to, fruit-based
alcohol-containing beverages, wines and beers.
[0136] When used in conjunction with, for example, a
.beta.-glucanase, the .beta.-glucosidase is effective for
hydrolyzing a variety of cellulose containing materials to glucose.
The glucose produced by enzymatic hydrolysis of the cellulose and
other glucose containing saccharides, may be recovered and stored,
or it may be subsequently fermented to ethanol using conventional
techniques. Many processes for the fermentation of glucose
generated from cellulose are well known, and are suitable for use
herein. Briefly, the hydrolyzate containing the glucose from the
enzymatic reaction is contacted with an appropriate microorganism
under conditions effective for the fermentation of the glucose to
ethanol. This fermentation may be separate from and follow the
enzymatic hydrolysis of the cellulose (sequentially processed), or
the hydrolysis and fermentation may be concurrent and conducted in
the same vessel (simultaneously processed). Details of the various
fermentation techniques, conditions, and suitable microorganisms
have been described, for example, by Wyman (1994, Bioresource
Technol., 50:3-16) or Olsson and Hahn-Hagerdal (1996, Enzyme
Microbial Technol., 18:312-331), the content of each of which is
incorporated herein by reference. Following the completion of a
fermentation, the alcohol may be recovered by extraction, and
optionally purified e.g., by distillation.
[0137] Thus, according to still another aspect of the present
invention there is provided a method of producing an alcohol. The
method according to this aspect of the present invention is
effected by fermenting a glucose containing fermentation starting
material by a cell overexpressing a nucleic acid construct
including a genomic, complementary or composite polynucleotide
preferably derived from Aspergillus niger, encoding a polypeptide
having a .beta.-glucosidase catalytic activity, and extracting the
alcohol therefrom. The polynucleotide preferably further encodes a
signal peptide in frame with the polypeptide. Still preferably, the
polynucleotide further encodes an endoplasmic reticulum retaining
peptide in frame with the polypeptide.
[0138] According to an additional aspect of the present invention
there is provided a method of producing an alcohol. The method
according to this aspect of the present invention is effected by
fermenting a plant derived glucose containing fermentation starting
material by a cell, the plant overexpressing a nucleic acid
construct including a genomic, complementary or composite
polynucleotide preferably derived from Aspergillus niger, encoding
a polypeptide having a .beta.-glucosidase catalytic activity, and
extracting the alcohol therefrom. The polynucleotide preferably
further encodes a signal peptide in frame with the polypeptide.
Still preferably, the polynucleotide further encodes an endoplasmic
reticulum retaining peptide in frame with the polypeptide.
[0139] Plants contain aroma and flavor compounds of glycosidic
nature, their inherent aroma property can be released by degrading
enzymes, turning a non-volatile aroma compound into its volatile
form. Thus, for example, .alpha.-L-arabinofuranosidases, assist in
the liberation of aroma compounds from substrates such as juices or
wines, as described by Gunata et al. (European Patent Application
No. 332.281, 1989; and "purification and some properties of an
alpha-L-arabinofuranosidase from A. niger action on grape
monoterpenyl arabinofuranosylglucosides. J. Agric. Food Chem. 38:
772-776, 1990). This outcome is achieved, for example, in a two
step process wherein the first step comprises the use of an
.alpha.-L-arabinofuranosidase, to catalyze the release of arabinose
residues from monoterpenyl .alpha.-L-arabinofuranosyl glucosides
contained in, for example, the fruit or vegetable juice via the
cleavage of the (1.fwdarw.6) linkage between a terminal
arabinofuranosyl unit and the intermediate glucose of a
monoterpenyl .alpha.-L-arabinofuranosylglucoside. The
.alpha.-L-arabinofuranosidase is preferably in a purified form so
as to avoid the undesirable degradation of other components of the
juice which may be detrimental to its ultimate quality. In the
second step, .beta.-glucosidase is required to yield the free
terpenol from the resulting desarabinosylated monoterpenyl
glucoside. If desired, both reaction steps may be performed in the
same reaction vessel without the need to isolate the intermediate
product (Gunata et al. (1989), supra). Thus, .beta.-glucosidase is
an essential contributor when the liberation of these aroma
compounds for improving the flavor of the juice or wine is desired.
Moreover, in the case of wine, the control of the liberation of
aroma compounds provides wines with a more consistent flavor, thus
reducing or eliminating the undesirable effect of "poor vintage
years". Additional information is contained in: "Cloning and
expression of DNA molecules encoding arabinan degrading enzyme of
fungal origin", U.S. Pat. No. 5,863,783; Y. Gueguen, et al. "A Very
Efficient .beta.-Glucosidase Catalyst for the Hydrolysis of Flavor
Precursors of Wines and Fruit Juices", J. Agric. Food Chem.
44:2336-2340, 1996, each of which is incorporated herein by
reference.
[0140] Thus, according to a further aspect of the present invention
there is provided a method of increasing a level of at least one
aroma substance in a plant derived product, such as, but not
limited to, an alcoholic beverage. The method according to this
aspect of the present invention is effected by incubating a glucose
containing plant starting material with a yeast cell overexpressing
a nucleic acid construct including a genomic, complementary or
composite polynucleotide preferably derived from Aspergillus niger
which encodes a polypeptide having a .beta.-glucosidase catalytic
activity, thereby increasing the level of the at least one aroma
substance in the plant derived product. The polynucleotide
preferably further encodes a signal peptide in frame with the
polypeptide. Still preferably, the polynucleotide further encodes
an endoplasmic reticulum retaining peptide in frame with the
polypeptide.
[0141] While reducing the present invention to practice it was
discovered that in order to obtain activity of a .beta.-glucosidase
in a transgenic plant, the expression construct should include a
signal peptide. In addition, it was found that retaining the enzyme
in the endoplasmic reticulum results in higher release of aroma
compounds following homogenization and incubation. It is assumed
that compartmentalization of the enzyme in for example the ER
prevents it from interacting with its substrates which are mainly
outside the cells, limiting such interaction following
homogenization. Indeed, directing the enzyme to the apoplast
resulted in increased release of aroma in vivo. Thus, depending on
the specific application, one can chose weather to include in the
construct an endoplasmic reticulum retaining peptide or not.
[0142] According to yet a further aspect of the present invention
there is provided a method of increasing a level of at least one
aroma substance in a plant derived product, such as, but not
limited to, an alcoholic beverage. The method according to this
aspect of the present invention is effected by incubating a glucose
containing plant starting material with a yeast cell, said plant
overexpressing a nucleic acid construct including a genomic,
complementary or composite polynucleotide preferably derived from
Aspergillus niger which encodes a polypeptide having a
.beta.-glucosidase catalytic activity, thereby increasing the level
of the at least one aroma substance in the plant derived product.
The polynucleotide preferably further encodes a signal peptide in
frame with the polypeptide. Still preferably, the polynucleotide
further encodes an endoplasmic reticulum retaining peptide in frame
with the polypeptide.
[0143] As used herein in the specification and in the claims
section that follows, the phrase "glucose containing starting
material" refers to any source of energy, in the form of glucose
containing compounds, other than free glucose, including, but not
limited to, crushed, minced, diced or extracted plant material,
plant, or portions thereof, such as fruits, examples thereof are
tropical fruits and grapes.
[0144] According to an additional aspect of the present invention
there is provided a method of producing an aroma spreading plant.
As used herein in the specification and in the claims section that
follows, the phrase "aroma spreading plant" refers to substantially
any part of a plant, in which volatile compounds are generated by
the catalytic activity of the .beta.-glucosidase polypeptide of the
present invention, release of volatile compounds therefrom is
perceived by the olfactory system of an organism, such as a
human.
[0145] The method according to this aspect of the present invention
is effected by overexpressing in the plant a nucleic acid construct
including a genomic, complementary or composite polynucleotide
derived from Aspergillus niger, which encodes a polypeptide having
a .beta.-glucosidase catalytic activity, thereby increasing aroma
spread from the plant. Such overexpression is preferably performed
in a tissue specific manner by, for example, employing a tissue
specific promoter, as hereinabove described, to thereby overexpress
a heterologous protein in a selected portion of the plant. The
tissue in which such overexpression is effected is selected
according to the availability of glucose containing non-volatile
aroma substrates therein. Thus, such an overexpression will cause
the release of a volatile and aroma constituent of the substrate.
Thus, according to preferred embodiments overexpressing the nucleic
acid construct is limited to at least one tissue, such as a flower,
a fruit, a seed, a root, a stem, pollen and leaves.
[0146] According to still a further aspect of the present invention
there is provided a method of increasing a level of free glucose in
a glucose containing fermentation starting material. The method
according to this aspect of the present invention is effected by
fermenting the glucose containing fermentation starting material by
a cell overexpressing a nucleic acid construct including a genomic,
complementary or composite polynucleotide preferably derived from
Aspergillus niger, which encodes a polypeptide having a glucosidase
catalytic activity, thereby increasing the level of the free
glucose in the glucose containing fermentation starting material.
The polynucleotide preferably further encodes a signal peptide in
frame with the polypeptide. Still preferably, the polynucleotide
further encodes an endoplasmic reticulum retaining peptide in frame
with the polypeptide.
[0147] According to another aspect of the present invention there
is provided a method of increasing a level of free glucose in a
plant derived glucose containing fermentation starting material.
The method according to this aspect of the present invention is
effected by fermenting the plant derived glucose containing
fermentation starting material by a cell, the plant overexpressing
a nucleic acid construct including a genomic, complementary or
composite polynucleotide preferably derived from Aspergillus niger,
which encodes a polypeptide having a .beta.-glucosidase catalytic
activity, thereby increasing the level of the free glucose in the
plant. The polynucleotide preferably further encodes a signal
peptide in frame with the polypeptide. Still preferably, the
polynucleotide further encodes an endoplasmic reticulum retaining
peptide in frame with the polypeptide.
[0148] As used herein in the specification and in the claims
section that follows, the term "free glucose" refers to glucose
residues in the form of a monosaccharide, the levels of which are
increased by the catalytic activity of .beta.-glucosidase.
[0149] As used herein in the specification and in the claims
section that follows, the phrase "glucose containing fermentation
starting material" refers to any source of energy, in the form of
glucose containing compounds, other than free glucose, including,
but not limited to, crushed, minced, diced or extracted plant
material, plant, or portions thereof, used in industrial
fermentation processes.
[0150] According to yet another aspect of the present invention
there is provided a method of increasing a level of extra- or
intracellular free glucose in a plant. The method according to this
aspect of the present invention is effected by overexpressing in
the plant a nucleic acid construct including a genomic,
complementary or composite polynucleotide preferably derived from
Aspergillus niger, which encodes a polypeptide having a
.beta.-glucosidase catalytic activity, thereby increasing the level
of the free glucose in the plant. Thus, sweeter fruits can be
produced. The polynucleotide preferably further encodes a signal
peptide in frame with the polypeptide. Still preferably, the
polynucleotide further encodes an endoplasmic reticulum retaining
peptide in frame with the polypeptide.
[0151] Glycosidases, including .beta.-glucosidase, catalyze
reactions involving the hydrolysis of O-glycosidic bond of
glycosides, and synthesize oligosaccharides when the reaction is
run in reverse from the normal direction, a result achieved by, for
example, site directed mutagenesis, and Km reversal. As described
in the Background section hereinabove, the hydrolysis reaction
mechanism of glycosidases involves two catalytic steps, the second
of which involves a base catalyzed H.sub.2O attack, resulting in
the regeneration of the enzyme, and the release of the saccharide
residue. Thus, in addition, oligosaccharide synthesis can be
achieved by adding a second saccharide to the reaction mixture,
which competes with the H.sub.2O molecule, and reacts in its place
with the first saccharide in, what is known as, a
transglycosylation reaction. Hence, as glycosidases are generally
available and easy to handle, these enzymes have the potential to
catalyze the production of many different products using
inexpensive substrates. For further detail see U.S. Pat. No.
5,716,812, which is incorporated herein by reference.
[0152] Thus, according to yet an additional aspect of the present
invention there is provided a method of synthesizing
oligosaccharides. The method according to this aspect of the
present invention is effected by mixing a polypeptide having a
.beta.-glucosidase catalytic activity with first and second
saccharide molecules to thereby join the first and second
saccharide molecules into an oligosaccharide.
[0153] Additional objects, advantages, and novel features of the
present invention will become apparent to one ordinarily skilled in
the art upon examination of the following examples, which are not
intended to be limiting. Additionally, each of the various
embodiments and aspects of the present invention as delineated
hereinabove and as claimed in the claims section below finds
experimental support in the following examples.
EXAMPLES
[0154] Reference is now made to the following examples, which
together with the above descriptions, illustrate the invention in a
non limiting fashion.
[0155] Generally, the nomenclature used herein and the laboratory
procedures utilized in the present invention include molecular,
biochemical, microbiological and recombinant DNA techniques. Such
techniques are thoroughly explained in the literature. See, for
example, "Molecular Cloning: A laboratory Manual" Sambrook et al.,
(1989); "Current Protocols in Molecular Biology" Volumes I-III
Ausubel, R. M., ed. (1994); Ausubel et al., "Current Protocols in
Molecular Biology", John Wiley and Sons, Baltimore, Md. (1989);
Perbal, "A Practical Guide to Molecular Cloning", John Wiley &
Sons, New York (1988); Watson et al., "Recombinant DNA", Scientific
American Books, New York; Birren et al. (eds) "Genome Analysis: A
Laboratory Manual Series", Vols. 1-4, Cold Spring Harbor Laboratory
Press, New York (1998); methodologies as set forth in U.S. Pat.
Nos. 4,666,828; 4,683,202; 4,801,531; 5,192,659 and 5,272,057;
"Cell Biology: A Laboratory Handbook", Volumes I-III Cellis, J. E.,
ed. (1994); "Current Protocols in" Volumes I-III Coligan J. E., ed.
(1994); Stites et al. (eds), "Basic and Clinical Immunology" (8th
Edition), Appleton & Lange, Norwalk, Conn. (1994); Mishell and
Shiigi (eds), "Selected Methods in Cellular Immunology", W. H.
Freeman and Co., New York (1980); available immunoassays are
extensively described in the patent and scientific liter, see, for
example, U.S. Pat. Nos. 3,791,932; 3,839,153; 3,850,752; 3,850,578;
3,853,987; 3,867,517; 3,879,262; 3,901,654; 3,935,074; 3,984,533;
3,996,345; 4,034,074; 4,098,876; 4,879,219; 5,011,771 and
5,281,521; "Oligonucleotide Synthesis" Gait, M. J., ed. (1984);
"Nucleic Acid Hybridization" Hames, B. D., and Higgins S. J., eds.
(1985); "Transcription and Translation" Hames, B. D., and Higgins
S. J., eds. (1984); "Animal Cell Culture" Freshney, R. I., ed.
(1986); "Immobilized Cells and Enzymes" IRL Press, (1986); "A
Practical Guide to Molecular Cloning" Perbal, B., (1984) and
"Methods in Enzymology" Vol. 1-317, Academic Press; "PCR Protocols:
A Guide To Methods And Application", Academic Press, San Diego,
Calif. (1990); Marshak et al., "Strategies for Protein Purification
and Characterization--A Laboratory Course Manual" CSHL Press
(1996); all of which are incorporated by reference as if fully set
forth herein. Other general references are provided throughout this
document. The procedures therein are believed to be well known in
the art and are provided for the convenience of the reader. All the
information contained therein is incorporated herein by
reference.
MATERIALS AND EXPERIMENTAL METHODS
[0156] Purification of A. niger .beta.-glucosidase:
[0157] A crude preparation of A. niger B1 (CMI CC 324626)
.beta.-glucosidase was obtained from Shaligal Ltd. (Tel-Aviv,
Israel). A sample (10 ml) of the crude enzyme (140 Units/ml) was
first diafiltered through a 50 kDa cut-off AMICON.TM. size
filtration membrane (Amicon Corp., Danvers, Mass.), with 20 mM
citrate buffer pH=5. The proteins were then separated on an FPLC
equipped with a MONO-Q.TM. anion exchange RH 5/5 column (Amersham
Pharmacia Biotech AB, Uppsala, Sweden), equilibrated with the same
buffer. The enzyme was eluted with a linear gradient of 0 to 350 mM
NaCl. Active fractions (see below, enzyme assays) were monitored
and pooled (between 80-110 mM NaCl). The partially purified enzyme
was dialyzed against 20 mM citrate buffer pH=3.5, applied to a
RESOURCE-S.TM. (Amersham Biosciences Inc, Piscatawy, N.J.) cation
exchange column equilibrated with the same buffer, and eluted with
a gradient of 0-1 M NaCl. The purified enzyme (eluted at 155 mM
NaCl) was concentrated by ultrafiltration (50 kDa cut-off membrane,
Amicon).
[0158] Enzyme Assays:
[0159] .beta.-glucosidase enzyme activity was monitored using a
plate assay as follows. 4-methylumbelife .beta.-D-glucopyranoside
(MUGlc, Sigma Chemical Inc. St. Louis, Mo.) to a final
concentration of 0.5 mM, was dissolved in PC buffer (50 mM
phosphate, 12 mM citric acid, pH=3.4) at 45.degree. C. The solution
was mixed with 3% agar in water, previously boiled and then cooled
to 45.degree. C. The resulting solution (20 ml) was poured into a
petri dish and after solidification, 10 .mu.l enzyme samples were
spotted. The plate was incubated at 50.degree. C. for one hour, and
then illuminated with long UV. An intense fluorescence was
indicative of .beta.-glucosidase activity.
[0160] Detection of .beta.-glucosidase in polyacrylamide gels was
carried out by washing the SDS-polyacrylamide gel with 1:1
isopropanol:PC buffer to remove SDS and renature the enzyme. The
gel was washed once in PC buffer and incubated in a thin layer of a
solution of 0.5 mM MUG1c. After incubation at 50.degree. C. for one
hour, the active protein band was visualized by UV light.
[0161] Quantitative assays were performed using pNPGlc as a
substrate according to Shoseyov (7).
[0162] Determination of Thermal Stability of A. niger
.beta.-Glucosidase:
[0163] Recombinant enzyme (40 .mu.g/ml) was dissolved in 20 mM
citrate phosphate buffer, pH=5. Each tested sample (811) was
covered by 1511 mineral oil. The activity was determined by the
standard pNPGlc assay (7).
[0164] Deglycosylation of A. niger .beta.-Glucosidase by
N-Glycosidase-F:
[0165] A N-glycosidase-F (Boehringer Mannheim, Mannheim, Germany)
reaction mixture, containing 0.125 .mu.g pure .beta.-glucosidase
(previously denatured by boiling for 3 minutes in 1% SDS and 5%
.beta.-mercaptoethanol), 0.2 units of the N-glycosidase-F, sodium
phosphate buffer (50 mM, pH=7.5), EDTA (25 mM), 1% Triton X-100 and
0.02% sodium azide, in a total volume of 12.5 .mu.l, was incubated
for 4 hours at 37.degree. C. Reaction was stopped by addition of
PAGE sample application buffer followed by 3 minutes of
boiling.
[0166] Proteolysis and N-Terminal Sequences of A. niger B1
.beta.-Glucosidase:
[0167] Partial enzymatic proteolysis with Staphylococcus aureus V8
protease was carried out as described by Cleveland (28). Briefly,
FPLC-purified .beta.-glucosidase (5 .mu.g), was concentrated by
acetone precipitation. The protein was separated on a preparative
10% SDS-PAGE. The gel was stained with coomassie blue, destained
and rinsed with cold water, and the .beta.-glucosidase protein band
was excised. The resulting gel slice was applied to a second
SDS-PAGE gel (15% acrylamide) and overlaid with Staphylococcus
aurous V8 protease. Digestion was carried out within the stacking
gel by turning off the current for 30 min. As the bromophenol blue
dye neared the bottom of the stacking gel, the current was
restored. The electrophoresed cleavage products were electroblotted
to PVDF membranes. The native protein was transferred to PVDF in
parallel. The N-terminal sequence of the native protein and two of
the numerous cleavage products were analyzed by Edman degradation
using a gas-phase protein sequencer (Applied Biosystems model 475A
microsequencer).
[0168] Cloning of bgl1 cDNA and Genomic Gene:
[0169] Total RNA isolation: Total RNA was isolated from Aspergillus
niger B1 as follows: A. niger B1 was grown in liquid culture
consisting of mineral media (NH.sub.4).sub.2SO.sub.4.3H.sub.2O (0.5
g/l), KH.sub.2PO.sub.4 (0.2 g/l), MgSO.sub.4 (0.2 g/l),
CaCl.sub.2.H.sub.2O (0.1 g/l), FeSO.sub.4.6H.sub.2O (0.001 g/l),
ZnSO.sub.4.7H.sub.2O (0.001 g/l), and 2 mM citric acid, at pH=3.5
with 1% w/v bran as a carbon source. The medium was autoclaved,
cooled and inoculated with A. niger B1 (10.sup.6 spores/ml).
Baffled flasks were used with constant shaking (200 RPM) at
37.degree. C. The appearance of .beta.-glucosidase activity was
monitored by placing 5 .mu.l of growth medium on 1% agar plates
containing 0.5 mM MUGlc, as described above. Activity was detected
following 15 hours incubation. The mycelium was harvested following
24 hours growth period, and the medium removed by filtering through
GFA.TM. glass microfibre (Whatman Inter. Ltd., Maidstone, England).
The mycelium was then frozen with liquid nitrogen and ground to
fine powder with mortar and pestle. Total RNA was produced from
this powder by the Guanidine thiocyanate (TRIREAGENT.TM.) method
(Molecular Research Center, Inc.).
[0170] RNA reverse-transcription reaction: cDNA was obtained by
reverse transcribing total RNA (10 .mu.g) using Stratagene RT-PCR
kit (Stratagene, La Jolla, Calif.). The reaction mixture (50 .mu.l)
additionally consisted of: Oligo dT18 (1 .mu.g), RNase Block
Ribonuclease Inhibitor (20 units), 1.times. buffer (50 mM Tris-HCl,
pH=8.3, 75 mM KCl, 10 mM DTT, 3 mM MgCl.sub.2), dNTPs (500 .mu.M
each) and reverse transcriptase (300 units). Total RNA was
initially denatured at 70.degree. C., allowed to cool to room
temperature (for primers annealing), and added to the reaction
mixture. The reaction mixture was incubated for 1 hour at
37.degree. C., followed by heating (95.degree. C., 5 minutes) and
stored at -70.degree. C. until further use.
[0171] DNA amplification: Degenerate primers for DNA amplification
reaction by PCR methods were synthesized, based on part of the
amino acid N-terminal sequence and an internal sequence, as
determined by the Edman degradation, following V8 proteolysis
(hereinbelow, experimental results). The partial sequence from
.beta.-glucosidase N-terminal derived amino acid sequence was
Ser-Pro-Pro-Tyr-Tyr-Pro (SEQ ID NO:4), yielding the following
primer: 5'-(C/G)(A/C/G/T)CC(A/C/G/T) CC(A/C/G/T)TA(C/T)TA(C/T)CC-3'
(SEQ ID NO:5). The partial sequence from E2 internal cleavage
product amino acid sequence was Gln-Pro-Ile-Leu-Pro-Ala-Gly-Gly
(SEQ ID NO:6), yielding the following primer:
5'-TCCIGC(T/G/C/A)GG(TG/C/A)A(G/A) (T/G/A)AT(T/G/C/A)GG(T/C)TG-3'
(SEQ ID NO: 7).
[0172] DNA amplification reaction mixture (2511) contained: reverse
transcriptase reaction product (1 .mu.l), 10.times.PCR buffer (2.5
.mu.l, Promega Corp., Madison, Wis.), dNTPs (250 .mu.M each),
MgCl.sub.2 (2.0 mM), degenerate primers (250 pmol each), DNA
polymerase (3 units, Stratagene, La Jolla, Calif.) and overlaid
with mineral oil (25 .mu.l). The reaction was performed in an
automated heating block (Programmable thermal controller--MJ
Research, Inc.). PCR cycling conditions were 30 seconds denaturing
at 94.degree. C., 60 seconds annealing at 50.degree. C., and 150
seconds elongation at 72.degree. C., repeated 36 times. The
resulting amplified product was electrophoresed on a 1.2% (w/v)
agarose/TBE gel, resulting in a 2.2 kb cDNA gene fragment, which
was further isolated using Gel Extraction Kit (QIAGEN, Hilden,
Germany) and cloned directly into the single 3'-T PCR insertion
site of pGEM-T cloning vector (Promega Corp., Madison, Wis.).
[0173] Probe preparation: The 2.2 kb partial cDNA was digested with
PstI to produce a 1.2 kb fragment DNA probe. A sample (25 ng) of
the fragment was labeled with [.sup.32P]dCTP, using the random
sequence nanonucleotide REDIPRIME.TM. DNA labeling system (Amersham
Pharmacia Biotech AB, Buckinghamshire, England).
[0174] Preparation of genomic DNA plasmid library: An A. niger B1
genomic library was constructed in the pYEAUra3 yeast/E. coli
shuttle vector (Clontech Lab. Inc. Palo Alto, Calif.). A. niger B1
was grown in liquid culture as described above, the mycelium
harvested following 48 hours of growth, frozen in liquid nitrogen
and grounded. The mycelium ground was used to produce genomic DNA
by the CTAB method of Murray and Thompson (29). The library was
constructed from partially digested Sau3A genomic DNA, cloned into
the BamHI site of the pYEUra3 yeast shuttle vector (Clontech Lab.
Inc. Palo Alto, Calif.). pYEAUra3 yeast/E. coli shuttle vector was
digested with BamHI and dephosphorylated with CIP to prevent self
ligation. The partially digested genomic DNA was cloned into the
shuttle vector with T4 ligase and used to transform TOP10 E. coli
electro-competent cells, which were then plated on LB-agar
containing ampicillin (50 .mu.g/ml). A total of 4.times.10.sup.4
colonies were grown on LB-agar plates, blotted to HYBOND-N.TM.
membranes (Amersham Pharmacia Biotech AB, Buckinghamshire, England)
and screened using the above described 1.2 kb probe. Positive
clones were subcloned in pUC18 and sequenced (Biological Services,
The Weizmann Institute of Science, Rehovot, Israel).
[0175] Expression of bgl1 cDNA in E. coli:
[0176] Two specific primers were designed according to the 5' and
the 3' sequences, corresponding to the N-terminal and C-terminal
region of the mature protein: sense primer: 5`-` (SEQ ID NO:8).
Antisense primer: 5'-AAAGGATCCTTAGTGAACAGTAGGCAGAGACGC-3' (SEQ ID
NO:9). The isolated cDNA was digested with NcoI and BamHI and
cloned into a pET3d expression vector (FIG. 1A, Novagen Inc.,
Madison, Wis.). Positive E. coli BL21 (DE3) pLysS colonies,
containing the bgl1 cDNA, were confirmed by enzyme restriction and
sequence analysis. Recombinant BGL1 was expressed according to the
manufacturer's protocol.
[0177] Expression of bgl1 cDNA in Saccharomyces cerevisiae and
Pichia pastoris:
[0178] The pYES2 vector (Invitrogen Inc., San Diego, Calif.) was
used to successfully clone the bgl1 cDNA gene into the
HindIII/BamHI of pYES2-bgl1 plasmid (FIG. 1b), and transform
Saccharomyces cerevisiae using the lithium acetate method (30). The
BGL1 was expressed by inducing the Gall promoter according to the
manufacturer's protocol. Saccharomyces cerevisiae strain INVSc2
(MATa, his3-D200, ura3-167) was used as the host. Pichia pastoris
strain GS115 (his4 mutant) was used as the host for shuttle and
expression vector plasmid pHIL-S1 (Invitrogen Inc., San Diego,
Calif.). The bgl1 cDNA was cloned into the EcoRI/BamHI sites of
pHIL-S1, yielding the pHIL-S1-bgl1 expression and secretion vector
(FIG. 1c). Expression in P. pastoris was carried out according to
the manufacturer's protocol. Screening of
.beta.-glucosidase-expressing clones was facilitated by top-agar,
containing 50 mg X-Glc, 30 ml methanol and 1% agar per liter. Blue
color indicated a colony producing active .beta.-glucosidase.
[0179] Western Blot Analysis:
[0180] Antibodies were produced from rabbit serum 36 days following
a second injection of 100 .mu.g purified protein and adjuvant
(AniLab Biological Services, Tal-Sachar, Israel). High molecular
weight ladder was from Sigma Chemical Inc. St. Louis, Mo. Western
blot conditions were as described in reference 36.
[0181] Determination of the Stereochemical Course of
Hydrolysis:
[0182] The method was essentially as described by Wong et al. (31).
PNPGlc (10 .mu.mols) was dissolved in 0.5 ml of 25 mM acetate
buffer pH=3.5 in D.sub.2O in an NMR tube. .beta.-Glucosidase was
lyophilized and redissolved in 100 .mu.l D.sub.2O (35 units/ml).
The .sup.1H-NMR spectrum of the substrate was recorded, enzyme
added (10 .mu.l), and spectra recorded at specified time intervals
on a Bruker AMX400 at 25.degree. C.
[0183] Inactivation and Reactivation Studies:
[0184] Pure A. niger .beta.-Glucosidase enzyme (0.47 mg/ml) was
incubated in the presence of various concentrations of
2-deoxy-2-fluoro-.beta.-glucosyl fluoride (2FGlcF, 0.5-6 mM) in 30
mM citrate buffer pH=4.8 at 50.degree. C. Residual enzyme activity
was determined at different time intervals by addition of an
aliquot (10 .mu.l) of the inactivation mixture, to a solution
containing citrate buffer (30 mM, pH=4.8), BSA (8 .mu.g) and
2,4-dinitrophenyl .beta.-D-glucopyranoside (DNPGlc, 0.625 mM, 830
.mu.l). Release of DNP was determined spectrophotometrically by
measuring the absorbance at 400 nm one minute after the addition of
the substrate.
[0185] Reactivation rates were determined as follows: pure A. niger
.beta.-glucosidase (0.34 mg/ml) was preincubated with 2FGlcF (5 mM)
for 15 min, after which the excess of the inactivator was
diafiltered by 20-kDa nominal molecular mass cutoff centrifugal
concentrators (Sartorius Inc., Goettingen, Germany). Samples of the
purified, inactivated enzyme were incubated in the presence
linamarin (0-16 mM) in citrate buffer (30 mM, pH=4.8) at 50.degree.
C. for 0, 10, 20 and 30 minutes, and the activity of each sample
was determined using p-nitrophenyl .beta.-D-glucopyranoside
(pNPGlc) as a substrate.
[0186] Expression of bgl1 cDNA in Tobacco Plants:
[0187] Genetic Constructs:
[0188] Bgl1 cDNA was cloned in pETBI (37). pJD330 and pBINPlus (38)
were used as an intermediate and binary vector, respectively. Cel1
signal sequence as well as 35S plus .OMEGA. fragment were retrieved
from pB21, modified pBLUESCRIPT.RTM. SK (39). Nicotiana tabacum cv.
Samson was used as a model plant for gene transformation. Three
gene constructs were employed (FIGS. 11a-c): (i) bgl1 without any
signal peptide which served for cytoplasmic expression (FIG. 11a,
plasmid pJDB1); (ii) bgl1 including a cell signal peptide at the N
terminus for secretion into the apoplast (FIG. 11b, plasmid
pJDCB1); and (iii) bgl1 including the cell signal peptide and the
KDEL (SEQ ID NO:24) ER-retaining peptide at the C-terminus for
accumulation in the ER (FIG. 11c, plasmid pJDCB1T).
[0189] To this end, bgl1 cDNA (2.5 kb) was released from pETB1 (37)
with NcoI and BamHI and inserted into pJD330 between the 35S
promoter .OMEGA. fragment and the nos terminator, eliminating the
gus gene, resulting in plasmid pJDB1. Endoplasmic reticulum
retaining signal tetrapeptide HDEL (SEQ ID NO:17) was synthesized
and fused with bgl1 at the C-terminal in pJDB1 by a fidelity PCR
reaction with the following pair of primers: Forward primer (23
mer), starting from nucleotide 1248 of bgl1 cDNA
5'-(1248)-CAGTGACCGTGGATGCGACAATG-(1270')-3' (SEQ ID NO:20);
Reverse primer (40 mer), starting at nucleotide 2506 of bgl1 cDNA
encoding also for the HDEL (SEQ ID NO:17) peptide
5'-(2506)-AGAGACGGATGACAAGTACTACTTGAAATTGGGCCCAAAA-3' (SEQ ID
NO:21). For pJDCB1T (35S .OMEGA.+Cel1+bgl1+HDEL, SEQ ID NO:17), the
35S .OMEGA. fragment of pJDB1 was replaced by a 35S .OMEGA.+Cel1
fragment digested from pB21 with BamHI and XbaI. For pJDCB1 (35S
.OMEGA.+Cel1+bgl1), the fragment containing 35S .OMEGA. and Cel1 as
well as part of bgl1 was cut from pJDCB1T with HindIII and NruI and
ligated with the vector of pJDB1 digested with the same pair of
restriction enzymes. The nucleotide sequence of all of the genetic
constructs was confirmed by DNA sequencing.
[0190] Gene cassettes in the intermediate vectors of pJDB1, pJDCB1
and pJDCB1T were further isolated with HindIII and EcoRI and
inserted into multiple cloning sites of the binary vector pBINPlus.
Disarmed Agrobaterium LB4404 was transformed with pBINPlus
containing bgl1 gene cassettes.
[0191] Tobacco Plant Transformation:
[0192] The young leaves of in vitro grown plantlets were excised
and cut into 0.5 cm.sup.2 pieces and then immersed for 5 minutes in
an overnight grown culture of Agrobacterium. After blotted with
sterile Whatman filter paper, the infected leaves were co-cultured
for 2 days with Agrobacterium on MS medium plus 2.0 mg/L of Zeatin
and 0.1 mg/L of IAA as well as 0.35% (w/v) phytagel and then
transferred to the same medium but with 300 mg/L kanamycin and 300
mg/L carbenicillin. Regenerates were then transferred to the
rooting media, containing only MS salts, vitamins and the same
antibiotics. Rooted plants were transferred to greenhouse after PCR
screening.
[0193] Screening for Transgenic Plants:
[0194] DNA and protein of plants were extracted according to Nagy
et al. (40). PCR verification of gene insertion into plant genome
was done with the following pairs of primers, which cover the DNA
fragment from position 1248 to the end of bgl1:
5'-CAGTGACCGTGGATGCGACAATG-3' (SEQ ID NO:22) and
5'-AAAGGATCCTTAGTGAACAGTAGGCAGAGACGC-3' (SEQ ID NO:23).
[0195] Identifying Transgenic Plants Expressing BGL1 Protein and
Activity:
[0196] Western blot (40) and SDS-PAGE activity gel staining (37)
were employed to screen successful transgenic lines, using the
purified A. niger BGL1 protein as positive controls and
non-transgenic plant as negative control.
[0197] SPMI-GC/MS Analysis:
[0198] The effect of bgl1 on flavor compound evolution and
composition was studied. Fresh leaves of transgenic plants and of
wild type control plants were excised and ground in liquid
nitrogen. Ice-cold extraction buffer, containing 10 mM EDTA, 4 mM
DTT in 50 mM phosphate buffer, pH 4.3, was added in a ratio of 1:3
w/w. The mixture was then shaken for 0.5 hours. 0.75 ml of
supernatant from each of the centrifuged mixtures was taken into a
glass vial. All manipulations were at 4.degree. C. After 9 hours of
incubation at 37.degree. C., the volatiles in the vial were
analyzed according to Clark et al. (41) using a Saturn Varian 3800
SPMI-GC-MS apparatus, equipped with a DB-5 capillary column. The
temperature of splitless injections was 250.degree. C. and the
transfer line was maintained at 280.degree. C. Helium was used as a
carrier gas. The oven was programmed as follows: 1 minute at
40.degree. C. with gradually heating to 250.degree. C. at a rate of
5.degree. C./minute.
Experimental Results
[0199] Purification of Wild Type A. niger .beta.-glucosidase:
[0200] A. niger .beta.-glucosidase enzyme preparation was purified
by MONO-Q.TM. (Amersham Biosciences Inc, Piasctawy, N.J.) FPLC.
Active protein samples eluted from the MONO-Q.TM. (Amersham
Biosciences Inc, Piscatawy, N.J.) anion exchange column were
separated on a 10% SDS-PAGE gel, stained with coomassie blue, and
incubated in the presence of MUGlc to demonstrate activity of the
enzyme. At this stage of purification, a discrete band, having an
apparent molecular mass of approximately 160 kDa and
.beta.-glucosidase activity could be detected (FIG. 2b, lanes 1-5:
1--electroeluted band of BGL1 from preparative PAGE-SDS gel stabs;
2-5--acetone precipitates from MONO-Q.TM. (Amersham Biosciences
Inc, Piscatawy, N.J.) anion exchange separation of BGL1). However,
the apparent mass of the denatured enzyme (boiled for 10 min in the
presence of .beta.-mercaptoethanol), was shown to be 120 kDa on 10%
SDS-PAGE (FIG. 2a). The enzyme was designated BGL1 was further
purified to homogeneity on a RESOURCE-S.TM. (Amersham Biosciences
Inc, Piscatawy, N.J.) cation exchange column (FIG. 3).
Deglycosylation of A. niger .beta.-glucosidase was performed by
N-glycosidase-F. As demonstrated in FIG. 4, SDS-PAGE analysis
indicated that approximately 20 kDa of the A. niger
.beta.-glucosidase mass can be attributed to N-linked
carbohydrates.
[0201] Proteolysis and N-Terminal Sequences of BGL1:
[0202] Partial enzymatic proteolysis with Staphylococcus aureus V8
protease of purified BGL1 was conducted. The undigested protein and
cleavage products were separated by SDS-PAGE, followed by
electroblotting onto PVDF membranes and determination of the
N-terminal sequence of the native protein and two of the cleavage
products. Amino acid sequences obtained were as follows:
[0203] N-terminal native protein:
Asp-Glu-Leu-Ala-Tyr-Ser-Pro-Pro-Tyr-Tyr-Pro-Ser-Pro-Trp-Ala-Asn-Gly-Gln-G-
ly-Asp (SEQ ID NO:10). Underlined portion represents SEQ ID
NO:4.
[0204] Internal cleavage product--E1 polypeptide:
Val-Leu-Lys-His-Lys-Asn-Gly-Val-Phe-Thr-Ala-Thr-Asp-Asn-Trp-Ala-Ile-Asp-G-
ln-Ile-Glu-Ala-Leu-Ala-Lys (SEQ ID NO: 11).
[0205] Internal cleavage product--E2 polypeptide:
Gly-Ala-Thr-Asp-Gly-Ser-Ala-Gln-Pro-Ile-Leu-Pro-Ala-Gly-Gly-Gly-Pro-Gly-G-
ly-Asn-Pro (SEQ ID NO:12). Underlined portion represents SEQ ID
NO:6.
[0206] FastA analysis (32) indicated that the N-terminal sequence,
as well as the internal sequences, have sequence similarity with
sequences of .beta.-glucosidase from the yeast Saccharomycopsis
fibuligera which belonging to Family 3 of the glycosyl
hydrolases.
[0207] Isolation and Characterization of bgl1 cDNA and Genomic
DNA:
[0208] In order to clone the A. niger .beta.-glucosidase gene,
degenerate primers were designed according to the sequence of
digest fragments of the polypeptide. These oligonucleotides were
used to amplify a cDNA fragment of the .beta.-glucosidase gene by
RT-PCR. A 1.2 kb probe was excised from the resultant 2.2 kb
amplification product and was used to screen a genomic library,
constructed in pYEUra3 yeast/E. coli shuttle vector. Positive
clones were successfully subcloned and sequenced, resulting in full
length bgl1 genomic sequence (SEQ ID NO:3, FIG. 5a). Amplification
primers were then generated, according to the genomic DNA sequence,
corresponding to the N- and C-terminal of the mature protein.
RT-PCR was thereafter used for amplifying the full length
.beta.-glucosidase cDNA sequence (SEQ ID NO:1, FIG. 5a, GenBank
Accession No. AJ132386). The cDNA sequence perfectly matched the
DNA sequence of the combined exons. The open reading frame was
found to encode a polypeptide with a predicted molecular weight of
92 kDa. The gene includes 7 exons intercepted by 6 introns (FIG.
5b). Analysis of the DNA sequence upstream to the sequence encoding
for the mature protein revealed a putative leader sequence,
intercepted by an 82 bp intron.
[0209] Production of rBGL1 in E. coli:
[0210] Recombinant BGL1 was overexpressed in E. coli. No apparent
.beta.-glucosidase activity could be detected in the E. coli
extracts, however SDS-PAGE analysis revealed a relatively intense
protein band expressed at the expected molecular weight. Western
blot analysis using rabbit polyclonal anti-native BGL1 antibodies
(AniLab Biological Services, Tal-Sachar, Israel), positively
identified the 90 kDa protein band (not shown). Further analysis
revealed that the protein was accumulated in inclusion bodies.
Several refolding experiments were conducted, however, these
efforts to produce active protein from E. coli failed (not
shown).
[0211] Expression of Recombinant BGL1 in S. cerevisiae and P.
pastoris:
[0212] Recombinant BGL1 was successfully expressed both in S.
cerevisiae and P. pastoris. In S. cerevisiae a relatively low level
of expression was found. The recombinant protein was detected by a
Western blot analysis (FIG. 6a). The total protein extract of S.
cerevisiae expressing bgl1 cDNA had a .beta.-glucosidase activity
of 1.9 units/mg protein. No .beta.-glucosidase activity was
detected in control S. cerevisiae, transformed with vector only,
under the same assay conditions. However, no protein band
corresponding to recombinant BGL1 could be detected by coomassie
blue staining. P. pastoris transformed with bgl1 secreted
relatively high levels of recombinant BGL1 to the medium (about 0.5
g/l) appearing as an almost pure protein in the culture supernatant
(FIG. 6b). This recombinant enzyme was highly active (124 units/mg
protein) and without further purification, yielded specific
activity similar to that of the pure native enzyme.
[0213] .sup.1H-NMR Determination of Stereochemical Outcome:
[0214] .sup.1H-NMR spectra of a reaction mixture containing pNPGlc
and BGL1 revealed that the beta anomer of glucose was formed first
(H-1=4.95 ppm), with delayed appearance of the alpha anomer
(H-15.59 ppm), the consequence of mutarotation (FIG. 7). BGL1 is
indeed, therefore, a retaining glycosidase, as has been observed
for other family members (33, 34).
[0215] Inactivation and Reactivation of A. niger
.beta.-glucosidase:
[0216] Enzyme was incubated in the presence of various
concentrations of 2FGlcF and residual enzyme activity was monitored
at different time intervals. Enzyme activity decreased in a
time-dependent manner, according to pseudo-first order kinetics,
allowing the determination of pseudo-first order rate constants:
K.sub.i=4.5 min.sup.-1 and K.sub.i=35.4 mM, for inactivation at
each inactivator concentration (0, 0.5, 1, 2, 4, and 6 mM, FIG.
8).
[0217] Rates of reactivation of 2-deoxy-2-fluoroglucosyl-BGL1 were
determined in the presence of different concentrations of linamarin
by monitoring activity regain after 0, 10, 20 and 30 min (FIG. 9).
The regain of activity followed a first order process at each
linamarin concentration.
[0218] Thermal stability of A. niger .beta.-glucosidase:
[0219] Thermal stability of the recombinant enzyme was evaluated at
different temperatures, presented as percent enzymatic activity
relative to an enzyme solution kept at 4.degree. C. Results
obtained are summarized in Table 2 and illustrated in FIG. 10. The
purified enzyme exhibits high thermal stability, as majority (above
50%) of the activity is maintained at a temperature ranging from
4-60.degree. C. TABLE-US-00002 TABLE 2 Temp. .degree. C. % activity
4 100 50 91.5 55 83.5 60 68 65 17.8
[0220] Expression of BGL1 in Tobacco Plants:
[0221] Agrobacterium mediated leaf disc transformation resulted in
transgenic tobacco plants as was proved by PCR (FIG. 12) for the
presence of the transgene, Western blotting (FIGS. 13a-b) for
presence of the protein and activity assays (FIGS. 14 and 15) for
presence of protein activity. Table 3 below summarizes the results.
TABLE-US-00003 TABLE 3 Gene construct BGL1 Cell + BGL1 + HDEL, Cell
+ BGL1 Number of 33 14 27 Regenerates PCR positive 29 9 23 Western
Blot 4 9 18 positive Activity gel 0 9 18 positive
[0222] Of the 29 PCR positive regenerates transformed with cDNA
encoding BGL1, which fails to encode a signal peptide, only in 4
the BGL1 protein was detectable via Western blotting, however no
BGL1 activity was measurable in any of which. The BGL1 was found
smaller in molecular weight compared to wild type A. niger
beta-glucosidase and of processed recombinant BGL1 containing a
signal peptide. Its apparent size of about 95 kDa is very close to
92 kDa which is the calculated molecular weight of the
un-glycosylated A. niger beta-glucosidase. This result coincides
with the fact that a protein with no signal peptide is expected to
be released from the ribosomes and remain in the cytoplast (42)
un-glycosylated, as protein glycosylation is conducted in the lumen
of the endoplasmic reticulum (43).
[0223] Of the 9 PCR positive regenerates transformed with a cDNA
encoding the BGL1 and a Cel1 signal peptide and in addition encodes
the HDEL, ER retaining peptide, all plants expressed detectable
amounts of BGL1 protein and activity.
[0224] Of the 23 PCR positive regenerates transformed with a cDNA
which encodes the BGL1 protein and the Cel1 signal peptide but not
the HDEL, ER retaining peptide, 18 plants expressed detectable
amounts of BGL1 protein and activity.
[0225] The Effect of BGL1 on Flavor Compound Evolution and
Composition in Transgenic Tobacco Plants:
[0226] Extracts of transgenic plants (CB14 and CBT21 containing
similar BGL1 activity, see FIG. 15) were incubated for 9 hours at
37.degree. C., and flavor compounds were analyzed by SPMI-GC/MS.
The results, which are summarized in Table 4 below, show that with
the exception of oleyl alcohol, the concentration of different
flavor compounds is increased in transgenic plants expressing
active BGL1 compared with the control. Furthermore, it seems that
compartmentalization of BGL1 in the ER (or for that matter, any
other subcellular organelle), rather then its secretion to the
apoplast, results in higher release of flavor compounds. It is
likely that this is resulted from the localization many flavor
compounds in the apoplast, thus, secretion of BGL1 to the apoplast
cause in vivo release of flavor compounds, while
compartmentalization of BGL1 in the ER results in release of flavor
compounds only in the event of cell disruption and
decompartmentalization. TABLE-US-00004 TABLE 4 Retention Time
(minutes) Scan Name CB14 CBT 21 3.917 419 Hexanal -.sup.a - 4.749
508 3-methyl-pentanoic acid - 4.863 520 2-Hexenal - +.sup.b 5.167
552 ? - + 6.564 702 1-Heptanol - - 7.1 752 ? + ++.sup.d 8.085 865
2-ethyl-1-pexanol - + 8.132 870 Limonene ++ + 8.194 877
2-methyl-phenol - + 10.653 1139 Menthol + + 11.757 1258 Nerol - +
12.039 1288 6-Quinolinol - + 12.1 1294 2-butyl-1-octanol - + 13.0
1458 ? - + 13.7 1466 ? - + 14.091 1507 Vitispirane - + 14.094 1516
4-[2,6,6-trimethyl-1-cyclohexen-1-yl] + ++ 3-Buten-1-one 15.985
1710 ? - - 19.327 2069 Oleyl alcohol --.sup.c -- CB14 - transgenic
plant containing Cel1 signal peptide + BGL1; CBT 21 - transgenic
plant containing Cel1 signal peptide + BGL1 + HDEL, ER retaining
peptide. .sup.a"-" means no significant difference in concentration
compared with wild type. .sup.b"+" means significant increase
compared with the wild type. .sup.c"--" means significant decrease
compared with the wild type. .sup.d"++" means significant increase
compared with a respective mark "+". ? - unknown compound.
[0227] Although the invention has been described in conjunction
with specific embodiments thereof, it is evident that many
alternatives, modifications and variations will be apparent to
those skilled in the art. Accordingly, it is intended to embrace
all such alternatives, modifications and variations that fall
within the spirit and broad scope of the appended claims. All
publications, patents, patent applications and sequences identified
by GenBank accession numbers mentioned in this specification are
herein incorporated in their entirety by reference into the
specification, to the same extent as if each individual
publication, patent, patent application or sequence was
specifically and individually indicated to be incorporated herein
by reference. In addition, citation or identification of any
reference in this application shall not be construed as an
admission that such reference is available as prior art to the
present invention.
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Sequence CWU 1
1
24 1 2583 DNA Aspergillus niger 1 atgaggttca ctttgatcga ggcggtggct
ctgactgccg tctcgctggc cagcgctgat 60 gaattggcct actccccacc
gtattaccca tccccttggg ccaatggcca gggcgactgg 120 gcgcaggcat
accagcgcgc tgttgatatt gtctcgcaaa tgacattgga tgagaaggtc 180
aatctgacca caggaactgg atgggaattg gaactatgtg ttggtcagac tggcggtgtt
240 ccccgattgg gagttccggg aatgtgttta caggatagcc ctctgggcgt
tcgcgactcc 300 gactacaact ctgctttccc tgccggcatg aacgtggctg
cgacctggga caagaatctg 360 gcataccttc gcggcaaggc tatgggtcag
gaatttagtg acaagggtgc cgatatccaa 420 ttgggtccag ctgccggccc
tctcggtaga agtcccgacg gtggtcgtaa ctgggagggc 480 ttctccccag
accctgccct aagtggtgtg ctctttgccg agaccatcaa gggtatccaa 540
gatgctggtg tggttgcgac ggctaagcac tacattgctt acgagcaaga gcatttccgt
600 caggcgcctg aagcccaagg ttttggattt aatatttccg agagtggaag
tgcgaacctc 660 gatgataaga ctatgcacga gctgtacctc tggcccttcg
cggatgccat ccgtgcaggt 720 gctggcgctg tgatgtgctc ctacaaccag
atcaacaaca gttatggctg ccagaacagc 780 tacactctga acaagctgct
caaggccgag ctgggcttcc agggctttgt catgagtgat 840 tgggctgctc
accatgctgg tgtgagtggt gctttggcag gattggatat gtctatgcca 900
ggagacgtcg actacgacag tggtacgtct tactggggta caaacttgac cattagcgtg
960 ctcaacggaa cggtgcccca atggcgtgtt gatgacatgg ctgtccgcat
catggccgcc 1020 tactacaagg tcggccgtga ccgtctgtgg actcctccca
acttcagctc atggaccaga 1080 gatgaatacg gctacaagta ctactacgtg
tcggagggac cgtacgagaa ggtcaaccag 1140 tacgtgaatg tgcaacgcaa
ccacagcgaa ctgattcgcc gcattggagc ggacagcacg 1200 gtgctcctca
agaacgacgg cgctctgcct ttgactggta aggagcgcct ggtcgcgctt 1260
atcggagaag atgcgggctc caacccttat ggtgccaacg gctgcagtga ccgtggatgc
1320 gacaatggaa cattggcgat gggctgggga agtggtactg ccaacttccc
atacctggtg 1380 acccccgagc aggccatctc aaacgaggtg cttaagcaca
agaatggtgt attcaccgcc 1440 accgataact gggctatcga tcaaattgag
gcgcttgcta agaccgccag tgtctctctt 1500 gtctttgtca acgccgactc
tggtgagggt tacatcaatg tggacggaaa cctgggtgac 1560 cgcaggaacc
tgaccctgtg gaggaacggc gataatgtga tcaaggctgc tgctagcaac 1620
tgcaacaaca caatcgttgt cattcactct gtcggaccag tcttggttaa cgagtggtac
1680 gacaacccca atgttaccgc tatcctctgg ggtggtttgc ccggtcagga
gtctggcaac 1740 tctcttgccg acgtcctcta tggccgtgtc aaccccggtg
ccaagtcgcc ctttacctgg 1800 ggcaagactc gtgaggccta ccaagactac
ttggtcaccg agcccaacaa cggcaacgga 1860 gcccctcagg aagactttgt
cgagggcgtc ttcattgact accgtggatt tgacaagcgc 1920 aacgagaccc
cgatctacga gttcggctat ggtctgagct acaccacttt caactactcg 1980
aaccttgagg tgcaggtgct gagcgcccct gcatacgagc ctgcttcggg tgagaccgag
2040 gcagcgccaa ccttcggaga ggttggaaat gcgtcggatt acctctaccc
cagcggattg 2100 ctgagaatta ccaagttcat ctacccctgg ctcaacggta
ccgatctcga ggcatcttcc 2160 ggggatgcta gctacgggca ggactcctcc
gactatcttc ccgagggagc caccgatggc 2220 tctgcgcaac cgatcctgcc
tgccggtggc ggtcctggcg gcaaccctcg cctgtacgac 2280 gagctcatcc
gcgtgtcagt gaccatcaag aacaccggca aggttgctgg tgatgaagtt 2340
ccccaactgt atgtttccct tggcggtccc aatgagccca agatcgtgct gcgtcaattc
2400 gagcgcatca cgctgcagcc gtcggaggag acgaagtgga gcacgactct
gacgcgccgt 2460 gaccttgcaa actggaatgt tgagaagcag gactgggaga
ttacgtcgta tcccaagatg 2520 gtgtttgtcg gaagctcctc gcggaagctg
ccgctccggg cgtctctgcc tactgttcac 2580 taa 2583 2 860 PRT
Aspergillus niger 2 Met Arg Phe Thr Leu Ile Glu Ala Val Ala Leu Thr
Ala Val Ser Leu 1 5 10 15 Ala Ser Ala Asp Glu Leu Ala Tyr Ser Pro
Pro Tyr Tyr Pro Ser Pro 20 25 30 Trp Ala Asn Gly Gln Gly Asp Trp
Ala Gln Ala Tyr Gln Arg Ala Val 35 40 45 Asp Ile Val Ser Gln Met
Thr Leu Asp Glu Lys Val Asn Leu Thr Thr 50 55 60 Gly Thr Gly Trp
Glu Leu Glu Leu Cys Val Gly Gln Thr Gly Gly Val 65 70 75 80 Pro Arg
Leu Gly Val Pro Gly Met Cys Leu Gln Asp Ser Pro Leu Gly 85 90 95
Val Arg Asp Ser Asp Tyr Asn Ser Ala Phe Pro Ala Gly Met Asn Val 100
105 110 Ala Ala Thr Trp Asp Lys Asn Leu Ala Tyr Leu Arg Gly Lys Ala
Met 115 120 125 Gly Gln Glu Phe Ser Asp Lys Gly Ala Asp Ile Gln Leu
Gly Pro Ala 130 135 140 Ala Gly Pro Leu Gly Arg Ser Pro Asp Gly Gly
Arg Asn Trp Glu Gly 145 150 155 160 Phe Ser Pro Asp Pro Ala Leu Ser
Gly Val Leu Phe Ala Glu Thr Ile 165 170 175 Lys Gly Ile Gln Asp Ala
Gly Val Val Ala Thr Ala Lys His Tyr Ile 180 185 190 Ala Tyr Glu Gln
Glu His Phe Arg Gln Ala Pro Glu Ala Gln Gly Phe 195 200 205 Gly Phe
Asn Ile Ser Glu Ser Gly Ser Ala Asn Leu Asp Asp Lys Thr 210 215 220
Met His Glu Leu Tyr Leu Trp Pro Phe Ala Asp Ala Ile Arg Ala Gly 225
230 235 240 Ala Gly Ala Val Met Cys Ser Tyr Asn Gln Ile Asn Asn Ser
Tyr Gly 245 250 255 Cys Gln Asn Ser Tyr Thr Leu Asn Lys Leu Leu Lys
Ala Glu Leu Gly 260 265 270 Phe Gln Gly Phe Val Met Ser Asp Trp Ala
Ala His His Ala Gly Val 275 280 285 Ser Gly Ala Leu Ala Gly Leu Asp
Met Ser Met Pro Gly Asp Val Asp 290 295 300 Tyr Asp Ser Gly Thr Ser
Tyr Trp Gly Thr Asn Leu Thr Ile Ser Val 305 310 315 320 Leu Asn Gly
Thr Val Pro Gln Trp Arg Val Asp Asp Met Ala Val Arg 325 330 335 Ile
Met Ala Ala Tyr Tyr Lys Val Gly Arg Asp Arg Leu Trp Thr Pro 340 345
350 Pro Asn Phe Ser Ser Trp Thr Arg Asp Glu Tyr Gly Tyr Lys Tyr Tyr
355 360 365 Tyr Val Ser Glu Gly Pro Tyr Glu Lys Val Asn Gln Tyr Val
Asn Val 370 375 380 Gln Arg Asn His Ser Glu Leu Ile Arg Arg Ile Gly
Ala Asp Ser Thr 385 390 395 400 Val Leu Leu Lys Asn Asp Gly Ala Leu
Pro Leu Thr Gly Lys Glu Arg 405 410 415 Leu Val Ala Leu Ile Gly Glu
Asp Ala Gly Ser Asn Pro Tyr Gly Ala 420 425 430 Asn Gly Cys Ser Asp
Arg Gly Cys Asp Asn Gly Thr Leu Ala Met Gly 435 440 445 Trp Gly Ser
Gly Thr Ala Asn Phe Pro Tyr Leu Val Thr Pro Glu Gln 450 455 460 Ala
Ile Ser Asn Glu Val Leu Lys His Lys Asn Gly Val Phe Thr Ala 465 470
475 480 Thr Asp Asn Trp Ala Ile Asp Gln Ile Glu Ala Leu Ala Lys Thr
Ala 485 490 495 Ser Val Ser Leu Val Phe Val Asn Ala Asp Ser Gly Glu
Gly Tyr Ile 500 505 510 Asn Val Asp Gly Asn Leu Gly Asp Arg Arg Asn
Leu Thr Leu Trp Arg 515 520 525 Asn Gly Asp Asn Val Ile Lys Ala Ala
Ala Ser Asn Cys Asn Asn Thr 530 535 540 Ile Val Val Ile His Ser Val
Gly Pro Val Leu Val Asn Glu Trp Tyr 545 550 555 560 Asp Asn Pro Asn
Val Thr Ala Ile Leu Trp Gly Gly Leu Pro Gly Gln 565 570 575 Glu Ser
Gly Asn Ser Leu Ala Asp Val Leu Tyr Gly Arg Val Asn Pro 580 585 590
Gly Ala Lys Ser Pro Phe Thr Trp Gly Lys Thr Arg Glu Ala Tyr Gln 595
600 605 Asp Tyr Leu Val Thr Glu Pro Asn Asn Gly Asn Gly Ala Pro Gln
Glu 610 615 620 Asp Phe Val Glu Gly Val Phe Ile Asp Tyr Arg Gly Phe
Asp Lys Arg 625 630 635 640 Asn Glu Thr Pro Ile Tyr Glu Phe Gly Tyr
Gly Leu Ser Tyr Thr Thr 645 650 655 Phe Asn Tyr Ser Asn Leu Glu Val
Gln Val Leu Ser Ala Pro Ala Tyr 660 665 670 Glu Pro Ala Ser Gly Glu
Thr Glu Ala Ala Pro Thr Phe Gly Glu Val 675 680 685 Gly Asn Ala Ser
Asp Tyr Leu Tyr Pro Ser Gly Leu Leu Arg Ile Thr 690 695 700 Lys Phe
Ile Tyr Pro Trp Leu Asn Gly Thr Asp Leu Glu Ala Ser Ser 705 710 715
720 Gly Asp Ala Ser Tyr Gly Gln Asp Ser Ser Asp Tyr Leu Pro Glu Gly
725 730 735 Ala Thr Asp Gly Ser Ala Gln Pro Ile Leu Pro Ala Gly Gly
Gly Pro 740 745 750 Gly Gly Asn Pro Arg Leu Tyr Asp Glu Leu Ile Arg
Val Ser Val Thr 755 760 765 Ile Lys Asn Thr Gly Lys Val Ala Gly Asp
Glu Val Pro Gln Leu Tyr 770 775 780 Val Ser Leu Gly Gly Pro Asn Glu
Pro Lys Ile Val Leu Arg Gln Phe 785 790 795 800 Glu Arg Ile Thr Leu
Gln Pro Ser Glu Glu Thr Lys Trp Ser Thr Thr 805 810 815 Leu Thr Arg
Arg Asp Leu Ala Asn Trp Asn Val Glu Lys Gln Asp Trp 820 825 830 Glu
Ile Thr Ser Tyr Pro Lys Met Val Phe Val Gly Ser Ser Ser Arg 835 840
845 Lys Leu Pro Leu Arg Ala Ser Leu Pro Thr Val His 850 855 860 3
3885 DNA Aspergillus niger 3 tccattcgcc catgcttagc gtgtcttttc
tttgaacact gcatgcggga ctgtgaattg 60 catgagtggg tagctttgcg
gagacagctg cactggcata catcatcgtt gggttcctca 120 attcgcatgc
cgtggcggac ggtcactttg tggcgctcaa actatttaat atggcccagc 180
tcccctttct ctcgctgttt tcgtttctgt cctccctaaa cctccagtct ctccattgga
240 caggtgttgc acggttgctc acctggtttg ttttgctccc cctttgggcg
accttgccat 300 catgaggttc actttgatcg aggcggtggc tctgactgcc
gtctcgctgg ccagcgctgt 360 acgtgccgtt actttgtcct gagaattgca
attgtgctta attagattca tttgtttgtt 420 tcatcatcgc tgacaatggt
cttttcatag gatgaattgg cctactcccc accgtattac 480 ccatcccctt
gggccaatgg ccagggcgac tgggcgcagg cataccagcg cgctgttgat 540
attgtctcgc aaatgacatt ggatgagaag gtcaatctga ccacaggaac tgggtagggc
600 ttacatggcg caatctgtat gctccggcta acaacttcta catgggaatt
ggaactatgt 660 gttggtcaga ctggcggtgt tccccggtag gtttgaaaat
attgtcgaga caggggacat 720 tattgattaa cggtgacaga ttgggagttc
cgggaatgtg tttacaggat agccctctgg 780 gcgttcgcga ctgtaagcca
tctgctgttg ttaggcttcg atgctcttac tgacacggcg 840 cagccgacta
caactctgct ttccctgccg gcatgaacgt ggctgcaacc tgggacaaga 900
atctggcata ccttcgcggc aaggctatgg gtcaggaatt tagtgacaag ggtgccgata
960 tccaattggg tccagctgcc ggccctctcg gtagaagtcc cgacggtggt
cgtaactggg 1020 agggcttctc cccagaccct gccctaagtg gtgtgctctt
tgccgagacc atcaagggta 1080 tccaagatgc tggtgtggtt gcgacggcta
agcactacat tgcttacgag caagagcatt 1140 tccgtcaggc gcctgaagcc
caaggttttg gatttaatat ttccgagagt ggaagtgcga 1200 acctcgatga
taagactatg cacgagctgt acctctggcc cttcgcggat gccatccgtg 1260
caggtgctgg cgctgtgatg tgctcctaca accagatcaa caacagttat ggctgccaga
1320 acagctacac tctgaacaag ctgctcaagg ccgagctggg cttccagggc
tttgtcatga 1380 gtgattgggc tgctcaccat gctggtgtga gtggtgcttt
ggcaggattg gatatgtcta 1440 tgccaggaga cgtcgactac gacagtggta
cgtcttactg gggtacaaac ttgaccatta 1500 gcgtgctcaa cggaacggtg
ccccaatggc gtgttgatga catggctgtc cgcatcatgg 1560 ccgcctacta
caaggtcggc cgtgaccgtc tgtggactcc tcccaacttc agctcatgga 1620
ccagagatga atacggctac aagtactact acgtgtcgga gggaccgtac gagaaggtca
1680 accagtacgt gaatgtgcaa cgcaaccaca gcgaactgat tcgccgcatt
ggagcggaca 1740 gcacggtgct cctcaagaac gacggcgctc tgcctttgac
tggtaaggag cgcctggtcg 1800 cgcttatcgg agaagatgcg ggctccaacc
cttatggtgc caacggctgc agtgaccgtg 1860 gatgcgacaa tggaacattg
gcgatgggct ggggaagtgg tactgccaac ttcccatacc 1920 tggtgacccc
cgagcaggcc atctcaaacg aggtgcttaa gcacaagaat ggtgtattca 1980
ccgccaccga taactgggct atcgatcaaa ttgaggcgct tgctaagacc gccaggtaag
2040 aagatccccg attcttttcc ttcttgtgca atggatgctg acaacatgct
agtgtctctc 2100 ttgtctttgt caacgccgac tctggtgagg gttacatcaa
tgtggacgga aacctgggtg 2160 accgcaggaa cctgaccctg tggaggaacc
gcgataatgt gatcaaggct gctgctagca 2220 actgcaacaa cacaatcgtt
gtcattcact ctgtcggacc agtcttggtt aacgagtggt 2280 acgacaaccc
caatgttacc gctatcctct ggggtggttt gcccggtcag gagtctggca 2340
actctcttgc cgacgtcctc tatggccgtg tcaaccccgg tgccaagtcg ccctttacct
2400 ggggcaagac tcgtgaggcc taccaagact acttggtcac cgagcccaac
aacggcaacg 2460 gagcccctca ggaagacttt gtcgagggcg tcttcattga
ctaccgtgga tttgacaagc 2520 gcaacgagac cccgatctac gagttcggct
atggtctgag ctacaccact ttcaactact 2580 cgaaccttga ggtgcaggtg
ctgagcgccc ctgcatacga gcctgcttcg ggtgagaccg 2640 aggcagcgcc
aaccttcgga gaggttggaa atgcgtcgga ttacctctac cccagcggat 2700
tgctgagaat taccaagttc atctacccct ggctcaacgg taccgatctc gaggcatctt
2760 ccggggatgc tagctacggg caggactcct ccgactatct tcccgaggga
gccaccgatg 2820 gctctgcgca accgatcctg cctgccggtg gcggtcctgg
cggcaaccct cgcctgtacg 2880 acgagctcat ccgcgtgtca gtgaccatca
agaacaccgg caaggttgct ggtgatgaag 2940 ttccccaact ggtaagtaaa
catgaggtcc gaacgaggtt gaacaaagct aatcagtcgc 3000 agtatgtttc
ccttggcggt cccaatgagc ccaagatcgt gctgcgtcaa ttcgagcgca 3060
tcacgctgca gccgtcggag gagacgaagt ggagcacgac tctgacgcgc cgtgaccttg
3120 caaactggaa tgttgagaag caggactggg agattacgtc gtatcccaag
atggtgtttg 3180 tcggaagctc ctcgcggaag ctgccgctcc gggcgtctct
gcctactgtt cactaaatag 3240 ctctcaaatg gtataccatg atggccgtgg
tatatgaatt aatgatttat gccaacagca 3300 agaccactgt agatgtagat
gtagaatgag tattgcgtag tagcgtgtag atgatgatac 3360 aagcgatccg
acacatggta ggaagagtgg cgctagttgg ggcggaaacc aagcgacgtc 3420
atccgctgcc gacttcgcca gtctttcttc ttttcctctt cagccttctt cctccgctta
3480 atccagcaac cattgccaat tgcctctaca acaactaatt gccataatac
tctactccta 3540 ttcaatatat acaccacaat ctcgacataa tcacacaagc
ctgaacacac gagcaaccat 3600 gccctctccc gatcctccag ccccagcgat
acgacccttc caaccaccca taacagcgct 3660 cctcatctac ccagcgaccc
taatcgtggg atcactcttc tccgtcctct ctcccaccgc 3720 acaaggcaca
cgcgacgacg gctccagcac cctccaccca cacgtcgagc ccctagcccc 3780
gtccatcgcg tcagacctca acctctcctt tcctccgccg cgccccgtca actacttcgc
3840 tcgcaaagac aacatcttca atctatattc gtcaaagtcg gctgg 3885 4 6 PRT
Aspergillus niger 4 Ser Pro Pro Tyr Tyr Pro 1 5 5 16 DNA Artificial
sequence Single strand DNA oligonucleotide misc_feature (2)..(2) n
is a, c, g, or t misc_feature (5)..(5) n is a, c, g, or t
misc_feature (8)..(8) n is a, c, g, or t 5 snccnccnta ytaycc 16 6 8
PRT Aspergillus niger 6 Gln Pro Ile Leu Pro Ala Gly Gly 1 5 7 20
DNA Artificial sequence Single strand DNA oligonucleotide
misc_feature (6)..(6) n is a, c, g, or t misc_feature (9)..(9) n is
a, c, g, or t misc_feature (15)..(15) n is a, c, g, or t 7
tccgcnggna rdatnggytg 20 8 34 DNA Artificial sequence Single strand
DNA oligonucleotide 8 aaaccatggc tgatgaattg gcatactccc cacc 34 9 33
DNA Artificial sequence Single strand DNA oligonucleotide 9
aaaggatcct tagtgaacag taggcagaga cgc 33 10 20 PRT Aspergillus niger
misc_feature A peptide derived from partial V8 proteolysis of
purified BGL1 10 Asp Glu Leu Ala Tyr Ser Pro Pro Tyr Tyr Pro Ser
Pro Trp Ala Asn 1 5 10 15 Gly Gln Gly Asp 20 11 25 PRT Aspergillus
niger misc_feature A peptide derived from partial V8 proteolysis of
purified BGL1 11 Val Leu Lys His Lys Asn Gly Val Phe Thr Ala Thr
Asp Asn Trp Ala 1 5 10 15 Ile Asp Gln Ile Glu Ala Leu Ala Lys 20 25
12 21 PRT Aspergillus niger misc_feature A peptide derived from
partial V8 proteolysis of purified BGL1 12 Gly Ala Thr Asp Gly Ser
Ala Gln Pro Ile Leu Pro Ala Gly Gly Gly 1 5 10 15 Pro Gly Gly Asn
Pro 20 13 3212 DNA Artificial sequence An expression cassettes used
for expression of A. niger beta-glucosidase in tobacco plants 13
gaattcccga tcctatctgt cacttcatca aaaggacagt agaaaaggaa ggtggcacta
60 caaatgccat cattgcgata aaggaaaggc tatcgttcaa gatgcctctg
ccgacagtgg 120 tcccaaagat ggacccccac ccacgaggag catcgtggaa
aaagaagacg ttccaaccac 180 gtcttcaaag caagtggatt gatgtgatat
ctccactgac gtaagggatg acgcacaatc 240 ccactatcct tcgcaagacc
cttcctctat ataaggaagt tcatttcatt tggagaggac 300 aggcttcttg
agatccttca acaattacca acaacaacaa acaacaaaca acattacaat 360
tactatttac aattacagtc gaccatggct gatgaattgg cctactcccc accgtattac
420 ccatcccctt gggccaatgg ccagggcgac tgggcgcagg cataccagcg
cgctgttgat 480 attgtctcgc aaatgacatt ggatgagaag gtcaatctga
ccacaggaac tggatgggaa 540 ttggaactat gtgttggtca gactggcggt
gttccccgat tgggagttcc gggaatgtgt 600 ttacaggata gccctctggg
cgttcgcgac tccgactaca actctgcttt ccctgccggc 660 atgaacgtgg
ctgcgacctg ggacaagaat ctggcatacc ttcgcggcaa ggctatgggt 720
caggaattta gtgacaaggg tgccgatatc caattgggtc cagctgccgg ccctctcggt
780 agaagtcccg acggtggtcg taactgggag ggcttctccc cagaccctgc
cctaagtggt 840 gtgctctttg ccgagaccat caagggtatc caagatgctg
gtgtggttgc gacggctaag 900 cactacattg cttacgagca agagcatttc
cgtcaggcgc ctgaagccca aggttttgga 960 tttaatattt ccgagagtgg
aagtgcgaac ctcgatgata agactatgca cgagctgtac 1020 ctctggccct
tcgcggatgc catccgtgca ggtgctggcg ctgtgatgtg ctcctacaac 1080
cagatcaaca acagttatgg ctgccagaac agctacactc tgaacaagct gctcaaggcc
1140 gagctgggct tccagggctt tgtcatgagt gattgggctg ctcaccatgc
tggtgtgagt 1200 ggtgctttgg caggattgga tatgtctatg ccaggagacg
tcgactacga cagtggtacg 1260 tcttactggg gtacaaactt gaccattagc
gtgctcaacg gaacggtgcc ccaatggcgt 1320 gttgatgaca tggctgtccg
catcatggcc gcctactaca aggtcggccg tgaccgtctg 1380 tggactcctc
ccaacttcag ctcatggacc agagatgaat acggctacaa gtactactac 1440
gtgtcggagg gaccgtacga gaaggtcaac cagtacgtga atgtgcaacg caaccacagc
1500 gaactgattc
gccgcattgg agcggacagc acggtgctcc tcaagaacga cggcgctctg 1560
cctttgactg gtaaggagcg cctggtcgcg cttatcggag aagatgcggg ctccaaccct
1620 tatggtgcca acggctgcag tgaccgtgga tgcgacaatg gaacattggc
gatgggctgg 1680 ggaagtggta ctgccaactt cccatacctg gtgacccccg
agcaggccat ctcaaacgag 1740 gtgcttaagc acaagaatgg tgtattcacc
gccaccgata actgggctat cgatcaaatt 1800 gaggcgcttg ctaagaccgc
cagtgtctct cttgtctttg tcaacgccga ctctggtgag 1860 ggttacatca
atgtggacgg aaacctgggt gaccgcagga acctgaccct gtggaggaac 1920
ggcgataatg tgatcaaggc tgctgctagc aactgcaaca acacaatcgt tgtcattcac
1980 tctgtcggac cagtcttggt taacgagtgg tacgacaacc ccaatgttac
cgctatcctc 2040 tggggtggtt tgcccggtca ggagtctggc aactctcttg
ccgacgtcct ctatggccgt 2100 gtcaaccccg gtgccaagtc gccctttacc
tggggcaaga ctcgtgaggc ctaccaagac 2160 tacttggtca ccgagcccaa
caacggcaac ggagcccctc aggaagactt tgtcgagggc 2220 gtcttcattg
actaccgtgg atttgacaag cgcaacgaga ccccgatcta cgagttcggc 2280
tatggtctga gctacaccac tttcaactac tcgaaccttg aggtgcaggt gctgagcgcc
2340 cctgcatacg agcctgcttc gggtgagacc gaggcagcgc caaccttcgg
agaggttgga 2400 aatgcgtcgg attacctcta ccccagcgga ttgctgagaa
ttaccaagtt catctacccc 2460 tggctcaacg gtaccgatct cgaggcatct
tccggggatg ctagctacgg gcaggactcc 2520 tccgactatc ttcccgaggg
agccaccgat ggctctgcgc aaccgatcct gcctgccggt 2580 ggcggtcctg
gcggcaaccc tcgcctgtac gacgagctca tccgcgtgtc agtgaccatc 2640
aagaacaccg gcaaggttgc tggtgatgaa gttccccaac tgtatgtttc ccttggcggt
2700 cccaatgagc ccaagatcgt gctgcgtcaa ttcgagcgca tcacgctgca
gccgtcggag 2760 gagacgaagt ggagcacgac tctgacgcgc cgtgaccttg
caaactggaa tgttgagaag 2820 caggactggg agattacgtc gtatcccaag
atggtgtttg tcggaagctc ctcgcggaag 2880 ctgccgctcc gggcgtctct
gcctactgtt cactaacccg ggcgagctcg aattgatcgt 2940 tcaaacattt
ggcaataaag tttcttaaga ttgaatcctg ttgccggtct tgcgatgatt 3000
atcatataat ttctgttgaa ttacgttaag catgtaataa ttaaacatgt aatgcatgac
3060 gttatttatg agatggggtt tttatgatta agagtccccg caattataca
ttttaatacg 3120 cgatagaaaa acaaaatata gcgcccaaac taaggataaa
attattcgcg ccgcgggggg 3180 gcattctatg gttactagat ctctagaatt cc 3212
14 841 PRT Artificial sequence the protein coded by An expression
cassettes used for expression of A. niger beta-glucosidase in
tobacco plants 14 Asp Glu Leu Ala Tyr Ser Pro Pro Tyr Tyr Pro Ser
Pro Trp Ala Asn 1 5 10 15 Gly Gln Gly Asp Trp Ala Gln Ala Tyr Gln
Arg Ala Val Asp Ile Val 20 25 30 Ser Gln Met Thr Leu Asp Glu Lys
Val Asn Leu Thr Thr Gly Thr Gly 35 40 45 Trp Glu Leu Glu Leu Cys
Val Gly Gln Thr Gly Gly Val Pro Arg Leu 50 55 60 Gly Val Pro Gly
Met Cys Leu Gln Asp Ser Pro Leu Gly Val Arg Asp 65 70 75 80 Ser Asp
Tyr Asn Ser Ala Phe Pro Ala Gly Met Asn Val Ala Ala Thr 85 90 95
Trp Asp Lys Asn Leu Ala Tyr Leu Arg Gly Lys Ala Met Gly Gln Glu 100
105 110 Phe Ser Asp Lys Gly Ala Asp Ile Gln Leu Gly Pro Ala Ala Gly
Pro 115 120 125 Leu Gly Arg Ser Pro Asp Gly Gly Arg Asn Trp Glu Gly
Phe Ser Pro 130 135 140 Asp Pro Ala Leu Ser Gly Val Leu Phe Ala Glu
Thr Ile Lys Gly Ile 145 150 155 160 Gln Asp Ala Gly Val Val Ala Thr
Ala Lys His Tyr Ile Ala Tyr Glu 165 170 175 Gln Glu His Phe Arg Gln
Ala Pro Glu Ala Gln Gly Phe Gly Phe Asn 180 185 190 Ile Ser Glu Ser
Gly Ser Ala Asn Leu Asp Asp Lys Thr Met His Glu 195 200 205 Leu Tyr
Leu Trp Pro Phe Ala Asp Ala Ile Arg Ala Gly Ala Gly Ala 210 215 220
Val Met Cys Ser Tyr Asn Gln Ile Asn Asn Ser Tyr Gly Cys Gln Asn 225
230 235 240 Ser Tyr Thr Leu Asn Lys Leu Leu Lys Ala Glu Leu Gly Phe
Gln Gly 245 250 255 Phe Val Met Ser Asp Trp Ala Ala His His Ala Gly
Val Ser Gly Ala 260 265 270 Leu Ala Gly Leu Asp Met Ser Met Pro Gly
Asp Val Asp Tyr Asp Ser 275 280 285 Gly Thr Ser Tyr Trp Gly Thr Asn
Leu Thr Ile Ser Val Leu Asn Gly 290 295 300 Thr Val Pro Gln Trp Arg
Val Asp Asp Met Ala Val Arg Ile Met Ala 305 310 315 320 Ala Tyr Tyr
Lys Val Gly Arg Asp Arg Leu Trp Thr Pro Pro Asn Phe 325 330 335 Ser
Ser Trp Thr Arg Asp Glu Tyr Gly Tyr Lys Tyr Tyr Tyr Val Ser 340 345
350 Glu Gly Pro Tyr Glu Lys Val Asn Gln Tyr Val Asn Val Gln Arg Asn
355 360 365 His Ser Glu Leu Ile Arg Arg Ile Gly Ala Asp Ser Thr Val
Leu Leu 370 375 380 Lys Asn Asp Gly Ala Leu Pro Leu Thr Gly Lys Glu
Arg Leu Val Ala 385 390 395 400 Leu Ile Gly Glu Asp Ala Gly Ser Asn
Pro Tyr Gly Ala Asn Gly Cys 405 410 415 Ser Asp Arg Gly Cys Asp Asn
Gly Thr Leu Ala Met Gly Trp Gly Ser 420 425 430 Gly Thr Ala Asn Phe
Pro Tyr Leu Val Thr Pro Glu Gln Ala Ile Ser 435 440 445 Asn Glu Val
Leu Lys His Lys Asn Gly Val Phe Thr Ala Thr Asp Asn 450 455 460 Trp
Ala Ile Asp Gln Ile Glu Ala Leu Ala Lys Thr Ala Ser Val Ser 465 470
475 480 Leu Val Phe Val Asn Ala Asp Ser Gly Glu Gly Tyr Ile Asn Val
Asp 485 490 495 Gly Asn Leu Gly Asp Arg Arg Asn Leu Thr Leu Trp Arg
Asn Gly Asp 500 505 510 Asn Val Ile Lys Ala Ala Ala Ser Asn Cys Asn
Asn Thr Ile Val Val 515 520 525 Ile His Ser Val Gly Pro Val Leu Val
Asn Glu Trp Tyr Asp Asn Pro 530 535 540 Asn Val Thr Ala Ile Leu Trp
Gly Gly Leu Pro Gly Gln Glu Ser Gly 545 550 555 560 Asn Ser Leu Ala
Asp Val Leu Tyr Gly Arg Val Asn Pro Gly Ala Lys 565 570 575 Ser Pro
Phe Thr Trp Gly Lys Thr Arg Glu Ala Tyr Gln Asp Tyr Leu 580 585 590
Val Thr Glu Pro Asn Asn Gly Asn Gly Ala Pro Gln Glu Asp Phe Val 595
600 605 Glu Gly Val Phe Ile Asp Tyr Arg Gly Phe Asp Lys Arg Asn Glu
Thr 610 615 620 Pro Ile Tyr Glu Phe Gly Tyr Gly Leu Ser Tyr Thr Thr
Phe Asn Tyr 625 630 635 640 Ser Asn Leu Glu Val Gln Val Leu Ser Ala
Pro Ala Tyr Glu Pro Ala 645 650 655 Ser Gly Glu Thr Glu Ala Ala Pro
Thr Phe Gly Glu Val Gly Asn Ala 660 665 670 Ser Asp Tyr Leu Tyr Pro
Ser Gly Leu Leu Arg Ile Thr Lys Phe Ile 675 680 685 Tyr Pro Trp Leu
Asn Gly Thr Asp Leu Glu Ala Ser Ser Gly Asp Ala 690 695 700 Ser Tyr
Gly Gln Asp Ser Ser Asp Tyr Leu Pro Glu Gly Ala Thr Asp 705 710 715
720 Gly Ser Ala Gln Pro Ile Leu Pro Ala Gly Gly Gly Pro Gly Gly Asn
725 730 735 Pro Arg Leu Tyr Asp Glu Leu Ile Arg Val Ser Val Thr Ile
Lys Asn 740 745 750 Thr Gly Lys Val Ala Gly Asp Glu Val Pro Gln Leu
Tyr Val Ser Leu 755 760 765 Gly Gly Pro Asn Glu Pro Lys Ile Val Leu
Arg Gln Phe Glu Arg Ile 770 775 780 Thr Leu Gln Pro Ser Glu Glu Thr
Lys Trp Ser Thr Thr Leu Thr Arg 785 790 795 800 Arg Asp Leu Ala Asn
Trp Asn Val Glu Lys Gln Asp Trp Glu Ile Thr 805 810 815 Ser Tyr Pro
Lys Met Val Phe Val Gly Ser Ser Ser Arg Lys Leu Pro 820 825 830 Leu
Arg Ala Ser Leu Pro Thr Val His 835 840 15 3329 DNA Artificial
sequence a cassette encoding a BGL1 fused to a Cel1 signal peptide
for secretion into the apoplast 15 gaattcccga tcctatctgt cacttcatca
aaaggacagt agaaaaggaa ggtggcacta 60 caaatgccat cattgcgata
aaggaaaggc tatcgttcaa gatgcctctg ccgacagtgg 120 tcccaaagat
ggacccccac ccacgaggag catcgtggaa aaagaagacg ttccaaccac 180
gtcttcaaag caagtggatt gatgtgatat ctccactgac gtaagggatg acgcacaatc
240 ccactatcct tcgcaagacc cttcctctat ataaggaagt tcatttcatt
tggagaggac 300 aggcttcttg agatccttca acaattacca acaacaacaa
acaacaaaca acattacaat 360 tactatttac aattacagtc gaggggatct
atggcgcgaa aatccctaat tttcccggtg 420 attttgctcg ccgttcttct
cttctctccg ccgatttact ccgccggtca cgattaccgc 480 gacgctctcc
gtaaatctag catggctgat gaattggcct actccccacc gtattaccca 540
tccccttggg ccaatggcca gggcgactgg gcgcaggcat accagcgcgc tgttgatatt
600 gtctcgcaaa tgacattgga tgagaaggtc aatctgacca caggaactgg
atgggaattg 660 gaactatgtg ttggtcagac tggcggtgtt ccccgattgg
gagttccggg aatgtgttta 720 caggatagcc ctctgggcgt tcgcgactcc
gactacaact ctgctttccc tgccggcatg 780 aacgtggctg cgacctggga
caagaatctg gcataccttc gcggcaaggc tatgggtcag 840 gaatttagtg
acaagggtgc cgatatccaa ttgggtccag ctgccggccc tctcggtaga 900
agtcccgacg gtggtcgtaa ctgggagggc ttctccccag accctgccct aagtggtgtg
960 ctctttgccg agaccatcaa gggtatccaa gatgctggtg tggttgcgac
ggctaagcac 1020 tacattgctt acgagcaaga gcatttccgt caggcgcctg
aagcccaagg ttttggattt 1080 aatatttccg agagtggaag tgcgaacctc
gatgataaga ctatgcacga gctgtacctc 1140 tggcccttcg cggatgccat
ccgtgcaggt gctggcgctg tgatgtgctc ctacaaccag 1200 atcaacaaca
gttatggctg ccagaacagc tacactctga acaagctgct caaggccgag 1260
ctgggcttcc agggctttgt catgagtgat tgggctgctc accatgctgg tgtgagtggt
1320 gctttggcag gattggatat gtctatgcca ggagacgtcg actacgacag
tggtacgtct 1380 tactggggta caaacttgac cattagcgtg ctcaacggaa
cggtgcccca atggcgtgtt 1440 gatgacatgg ctgtccgcat catggccgcc
tactacaagg tcggccgtga ccgtctgtgg 1500 actcctccca acttcagctc
atggaccaga gatgaatacg gctacaagta ctactacgtg 1560 tcggagggac
cgtacgagaa ggtcaaccag tacgtgaatg tgcaacgcaa ccacagcgaa 1620
ctgattcgcc gcattggagc ggacagcacg gtgctcctca agaacgacgg cgctctgcct
1680 ttgactggta aggagcgcct ggtcgcgctt atcggagaag atgcgggctc
caacccttat 1740 ggtgccaacg gctgcagtga ccgtggatgc gacaatggaa
cattggcgat gggctgggga 1800 agtggtactg ccaacttccc atacctggtg
acccccgagc aggccatctc aaacgaggtg 1860 cttaagcaca agaatggtgt
attcaccgcc accgataact gggctatcga tcaaattgag 1920 gcgcttgcta
agaccgccag tgtctctctt gtctttgtca acgccgactc tggtgagggt 1980
tacatcaatg tggacggaaa cctgggtgac cgcaggaacc tgaccctgtg gaggaacggc
2040 gataatgtga tcaaggctgc tgctagcaac tgcaacaaca caatcgttgt
cattcactct 2100 gtcggaccag tcttggttaa cgagtggtac gacaacccca
atgttaccgc tatcctctgg 2160 ggtggtttgc ccggtcagga gtctggcaac
tctcttgccg acgtcctcta tggccgtgtc 2220 aaccccggtg ccaagtcgcc
ctttacctgg ggcaagactc gtgaggccta ccaagactac 2280 ttggtcaccg
agcccaacaa cggcaacgga gcccctcagg aagactttgt cgagggcgtc 2340
ttcattgact accgtggatt tgacaagcgc aacgagaccc cgatctacga gttcggctat
2400 ggtctgagct acaccacttt caactactcg aaccttgagg tgcaggtgct
gagcgcccct 2460 gcatacgagc ctgcttcggg tgagaccgag gcagcgccaa
ccttcggaga ggttggaaat 2520 gcgtcggatt acctctaccc cagcggattg
ctgagaatta ccaagttcat ctacccctgg 2580 ctcaacggta ccgatctcga
ggcatcttcc ggggatgcta gctacgggca ggactcctcc 2640 gactatcttc
ccgagggagc caccgatggc tctgcgcaac cgatcctgcc tgccggtggc 2700
ggtcctggcg gcaaccctcg cctgtacgac gagctcatcc gcgtgtcagt gaccatcaag
2760 aacaccggca aggttgctgg tgatgaagtt ccccaactgt atgtttccct
tggcggtccc 2820 aatgagccca agatcgtgct gcgtcaattc gagcgcatca
cgctgcagcc gtcggaggag 2880 acgaagtgga gcacgactct gacgcgccgt
gaccttgcaa actggaatgt tgagaagcag 2940 gactgggaga ttacgtcgta
tcccaagatg gtgtttgtcg gaagctcctc gcggaagctg 3000 ccgctccggg
cgtctctgcc tactgttcac taacccgggc gagctcgaat tgatcgttca 3060
aacatttggc aataaagttt cttaagattg aatcctgttg ccggtcttgc gatgattatc
3120 atataatttc tgttgaatta cgttaagcat gtaataatta aacatgtaat
gcatgacgtt 3180 atttatgaga tggggttttt atgattaaga gtccccgcaa
ttatacattt taatacgcga 3240 tagaaaaaca aaatatagcg cccaaactaa
ggataaaatt attcgcgccg cgggggggca 3300 ttctatggtt actagatctc
tagaattcc 3329 16 880 PRT Artificial sequence BGL1 fused to a Cel1
signal peptide for secretion into the apoplast 16 Met Ala Arg Lys
Ser Leu Ile Phe Pro Val Ile Leu Leu Ala Val Leu 1 5 10 15 Leu Phe
Ser Pro Pro Ile Tyr Ser Ala Gly His Asp Tyr Arg Asp Ala 20 25 30
Leu Arg Lys Ser Ser Met Ala Asp Glu Leu Ala Tyr Ser Pro Pro Tyr 35
40 45 Tyr Pro Ser Pro Trp Ala Asn Gly Gln Gly Asp Trp Ala Gln Ala
Tyr 50 55 60 Gln Arg Ala Val Asp Ile Val Ser Gln Met Thr Leu Asp
Glu Lys Val 65 70 75 80 Asn Leu Thr Thr Gly Thr Gly Trp Glu Leu Glu
Leu Cys Val Gly Gln 85 90 95 Thr Gly Gly Val Pro Arg Leu Gly Val
Pro Gly Met Cys Leu Gln Asp 100 105 110 Ser Pro Leu Gly Val Arg Asp
Ser Asp Tyr Asn Ser Ala Phe Pro Ala 115 120 125 Gly Met Asn Val Ala
Ala Thr Trp Asp Lys Asn Leu Ala Tyr Leu Arg 130 135 140 Gly Lys Ala
Met Gly Gln Glu Phe Ser Asp Lys Gly Ala Asp Ile Gln 145 150 155 160
Leu Gly Pro Ala Ala Gly Pro Leu Gly Arg Ser Pro Asp Gly Gly Arg 165
170 175 Asn Trp Glu Gly Phe Ser Pro Asp Pro Ala Leu Ser Gly Val Leu
Phe 180 185 190 Ala Glu Thr Ile Lys Gly Ile Gln Asp Ala Gly Val Val
Ala Thr Ala 195 200 205 Lys His Tyr Ile Ala Tyr Glu Gln Glu His Phe
Arg Gln Ala Pro Glu 210 215 220 Ala Gln Gly Phe Gly Phe Asn Ile Ser
Glu Ser Gly Ser Ala Asn Leu 225 230 235 240 Asp Asp Lys Thr Met His
Glu Leu Tyr Leu Trp Pro Phe Ala Asp Ala 245 250 255 Ile Arg Ala Gly
Ala Gly Ala Val Met Cys Ser Tyr Asn Gln Ile Asn 260 265 270 Asn Ser
Tyr Gly Cys Gln Asn Ser Tyr Thr Leu Asn Lys Leu Leu Lys 275 280 285
Ala Glu Leu Gly Phe Gln Gly Phe Val Met Ser Asp Trp Ala Ala His 290
295 300 His Ala Gly Val Ser Gly Ala Leu Ala Gly Leu Asp Met Ser Met
Pro 305 310 315 320 Gly Asp Val Asp Tyr Asp Ser Gly Thr Ser Tyr Trp
Gly Thr Asn Leu 325 330 335 Thr Ile Ser Val Leu Asn Gly Thr Val Pro
Gln Trp Arg Val Asp Asp 340 345 350 Met Ala Val Arg Ile Met Ala Ala
Tyr Tyr Lys Val Gly Arg Asp Arg 355 360 365 Leu Trp Thr Pro Pro Asn
Phe Ser Ser Trp Thr Arg Asp Glu Tyr Gly 370 375 380 Tyr Lys Tyr Tyr
Tyr Val Ser Glu Gly Pro Tyr Glu Lys Val Asn Gln 385 390 395 400 Tyr
Val Asn Val Gln Arg Asn His Ser Glu Leu Ile Arg Arg Ile Gly 405 410
415 Ala Asp Ser Thr Val Leu Leu Lys Asn Asp Gly Ala Leu Pro Leu Thr
420 425 430 Gly Lys Glu Arg Leu Val Ala Leu Ile Gly Glu Asp Ala Gly
Ser Asn 435 440 445 Pro Tyr Gly Ala Asn Gly Cys Ser Asp Arg Gly Cys
Asp Asn Gly Thr 450 455 460 Leu Ala Met Gly Trp Gly Ser Gly Thr Ala
Asn Phe Pro Tyr Leu Val 465 470 475 480 Thr Pro Glu Gln Ala Ile Ser
Asn Glu Val Leu Lys His Lys Asn Gly 485 490 495 Val Phe Thr Ala Thr
Asp Asn Trp Ala Ile Asp Gln Ile Glu Ala Leu 500 505 510 Ala Lys Thr
Ala Ser Val Ser Leu Val Phe Val Asn Ala Asp Ser Gly 515 520 525 Glu
Gly Tyr Ile Asn Val Asp Gly Asn Leu Gly Asp Arg Arg Asn Leu 530 535
540 Thr Leu Trp Arg Asn Gly Asp Asn Val Ile Lys Ala Ala Ala Ser Asn
545 550 555 560 Cys Asn Asn Thr Ile Val Val Ile His Ser Val Gly Pro
Val Leu Val 565 570 575 Asn Glu Trp Tyr Asp Asn Pro Asn Val Thr Ala
Ile Leu Trp Gly Gly 580 585 590 Leu Pro Gly Gln Glu Ser Gly Asn Ser
Leu Ala Asp Val Leu Tyr Gly 595 600 605 Arg Val Asn Pro Gly Ala Lys
Ser Pro Phe Thr Trp Gly Lys Thr Arg 610 615 620 Glu Ala Tyr Gln Asp
Tyr Leu Val Thr Glu Pro Asn Asn Gly Asn Gly 625 630 635 640 Ala Pro
Gln Glu Asp Phe Val Glu Gly Val Phe Ile Asp Tyr Arg Gly 645 650 655
Phe Asp Lys Arg Asn Glu Thr Pro Ile Tyr Glu Phe Gly Tyr Gly Leu 660
665 670 Ser Tyr Thr Thr Phe Asn Tyr Ser Asn Leu Glu Val Gln Val Leu
Ser 675 680 685 Ala Pro Ala Tyr Glu Pro Ala Ser Gly Glu Thr Glu Ala
Ala Pro Thr 690 695 700 Phe Gly Glu Val Gly Asn Ala Ser Asp Tyr Leu
Tyr Pro Ser Gly Leu 705 710 715 720 Leu Arg Ile Thr Lys Phe Ile Tyr
Pro Trp Leu Asn Gly Thr
Asp Leu 725 730 735 Glu Ala Ser Ser Gly Asp Ala Ser Tyr Gly Gln Asp
Ser Ser Asp Tyr 740 745 750 Leu Pro Glu Gly Ala Thr Asp Gly Ser Ala
Gln Pro Ile Leu Pro Ala 755 760 765 Gly Gly Gly Pro Gly Gly Asn Pro
Arg Leu Tyr Asp Glu Leu Ile Arg 770 775 780 Val Ser Val Thr Ile Lys
Asn Thr Gly Lys Val Ala Gly Asp Glu Val 785 790 795 800 Pro Gln Leu
Tyr Val Ser Leu Gly Gly Pro Asn Glu Pro Lys Ile Val 805 810 815 Leu
Arg Gln Phe Glu Arg Ile Thr Leu Gln Pro Ser Glu Glu Thr Lys 820 825
830 Trp Ser Thr Thr Leu Thr Arg Arg Asp Leu Ala Asn Trp Asn Val Glu
835 840 845 Lys Gln Asp Trp Glu Ile Thr Ser Tyr Pro Lys Met Val Phe
Val Gly 850 855 860 Ser Ser Ser Arg Lys Leu Pro Leu Arg Ala Ser Leu
Pro Thr Val His 865 870 875 880 17 4 PRT Artificial sequence ER
retaining signal peptide 17 His Asp Glu Leu 1 18 3288 DNA
Artificial sequence a cassette encoding a BGL1 fused to Cel1 signal
peptide and a HDEL ER-retaining peptide 18 gaattcccga tcctatctgt
cacttcatca aaaggacagt agaaaaggaa ggtggcacta 60 caaatgccat
cattgcgata aaggaaaggc tatcgttcaa gatgcctctg ccgacagtgg 120
tcccaaagat ggacccccac ccacgaggag catcgtggaa aaagaagacg ttccaaccac
180 gtcttcaaag caagtggatt gatgtgatat ctccactgac gtaagggatg
acgcacaatc 240 ccactatcct tcgcaagacc cttcctctat ataaggaagt
tcatttcatt tggagaggac 300 aggcttcttg agatccttca acaattacca
acaacaacaa acaacaaaca acattacaat 360 tactatttac aattacagtc
gaggggatct atggcgcgaa aatccctaat tttcccggtg 420 attttgctcg
ccgttcttct cttctctccg ccgatttact ccgccggtca cgattaccgc 480
gacgctctcc gtaaatctag catggctgat gaattggcct actccccacc gtattaccca
540 tccccttggg ccaatggcca gggcgactgg gcgcaggcat accagcgcgc
tgttgatatt 600 gtctcgcaaa tgacattgga tgagaaggtc aatctgacca
caggaactgg atgggaattg 660 gaactatgtg ttggtcagac tggcggtgtt
ccccgattgg gagttccggg aatgtgttta 720 caggatagcc ctctgggcgt
tcgcgactcc gactacaact ctgctttccc tgccggcatg 780 aacgtggctg
cgacctggga caagaatctg gcataccttc gcggcaaggc tatgggtcag 840
gaatttagtg acaagggtgc cgatatccaa ttgggtccag ctgccggccc tctcggtaga
900 agtcccgacg gtggtcgtaa ctgggagggc ttctccccag accctgccct
aagtggtgtg 960 ctctttgccg agaccatcaa gggtatccaa gatgctggtg
tggttgcgac ggctaagcac 1020 tacattgctt acgagcaaga gcatttccgt
caggcgcctg aagcccaagg ttttggattt 1080 aatatttccg agagtggaag
tgcgaacctc gatgataaga ctatgcacga gctgtacctc 1140 tggcccttcg
cggatgccat ccgtgcaggt gctggcgctg tgatgtgctc ctacaaccag 1200
atcaacaaca gttatggctg ccagaacagc tacactctga acaagctgct caaggccgag
1260 ctgggcttcc agggctttgt catgagtgat tgggctgctc accatgctgg
tgtgagtggt 1320 gctttggcag gattggatat gtctatgcca ggagacgtcg
actacgacag tggtacgtct 1380 tactggggta caaacttgac cattagcgtg
ctcaacggaa cggtgcccca atggcgtgtt 1440 gatgacatgg ctgtccgcat
catggccgcc tactacaagg tcggccgtga ccgtctgtgg 1500 actcctccca
acttcagctc atggaccaga gatgaatacg gctacaagta ctactacgtg 1560
tcggagggac cgtacgagaa ggtcaaccag tacgtgaatg tgcaacgcaa ccacagcgaa
1620 ctgattcgcc gcattggagc ggacagcacg gtgctcctca agaacgacgg
cgctctgcct 1680 ttgactggta aggagcgcct ggtcgcgctt atcggagaag
atgcgggctc caacccttat 1740 ggtgccaacg gctgcagtga ccgtggatgc
gacaatggaa cattggcgat gggctgggga 1800 agtggtactg ccaacttccc
atacctggtg acccccgagc aggccatctc aaacgaggtg 1860 cttaagcaca
agaatggtgt attcaccgcc accgataact gggctatcga tcaaattgag 1920
gcgcttgcta agaccgccag tgtctctctt gtctttgtca acgccgactc tggtgagggt
1980 tacatcaatg tggacggaaa cctgggtgac cgcaggaacc tgaccctgtg
gaggaacggc 2040 gataatgtga tcaaggctgc tgctagcaac tgcaacaaca
caatcgttgt cattcactct 2100 gtcggaccag tcttggttaa cgagtggtac
gacaacccca atgttaccgc tatcctctgg 2160 ggtggtttgc ccggtcagga
gtctggcaac tctcttgccg acgtcctcta tggccgtgtc 2220 aaccccggtg
ccaagtcgcc ctttacctgg ggcaagactc gtgaggccta ccaagactac 2280
ttggtcaccg agcccaacaa cggcaacgga gcccctcagg aagactttgt cgagggcgtc
2340 ttcattgact accgtggatt tgacaagcgc aacgagaccc cgatctacga
gttcggctat 2400 ggtctgagct acaccacttt caactactcg aaccttgagg
tgcaggtgct gagcgcccct 2460 gcatacgagc ctgcttcggg tgagaccgag
gcagcgccaa ccttcggaga ggttggaaat 2520 gcgtcggatt acctctaccc
cagcggattg ctgagaatta ccaagttcat ctacccctgg 2580 ctcaacggta
ccgatctcga ggcatcttcc ggggatgcta gctacgggca ggactcctcc 2640
gactatcttc ccgagggagc caccgatggc tctgcgcaac cgatcctgcc tgccggtggc
2700 ggtcctggcg gcaaccctcg cctgtacgac gagctcatcc gcgtgtcagt
gaccatcaag 2760 aacaccggca aggttgctgg tgatgaagtt ccccaactgt
atgtttccct tggcggtccc 2820 aatgagccca agatcgtgct gcgtcaattc
gagcgcatca cgctgcagcc gtcggaggag 2880 acgaagtgga gcacgactct
gacgcgccgt gaccttgcaa actggaatgt tgagaagcag 2940 gactgggaga
ttacgtcgta tcccaagatg gtgtttgtcg gaagctcctc gcggaagctg 3000
ccgctccggg cgtctctgcc tactgttcat gatgaacttt aacccgggcg agctcgaatt
3060 gatcgttcaa acatttggca ataaagtttc ttaagattga gttaagcatg
taataattaa 3120 acatgtaatg catgacgtta tttatgagat ggggttttta
tgattaagag tccccgcaat 3180 tatacatttt aatacgcgat agaaaaacaa
aatatagcgc ccaaactaag gataaaatta 3240 ttcgcgccgc gggggggcat
tctatggtta ctagatctct agaattcc 3288 19 883 PRT Artificial sequence
BGL1 fused to Cel1 signal peptide and a HDEL ER-retaining peptide
19 Met Ala Arg Lys Ser Leu Ile Phe Pro Val Ile Leu Leu Ala Val Leu
1 5 10 15 Leu Phe Ser Pro Pro Ile Tyr Ser Ala Gly His Asp Tyr Arg
Asp Ala 20 25 30 Leu Arg Lys Ser Ser Met Ala Asp Glu Leu Ala Tyr
Ser Pro Pro Tyr 35 40 45 Tyr Pro Ser Pro Trp Ala Asn Gly Gln Gly
Asp Trp Ala Gln Ala Tyr 50 55 60 Gln Arg Ala Val Asp Ile Val Ser
Gln Met Thr Leu Asp Glu Lys Val 65 70 75 80 Asn Leu Thr Thr Gly Thr
Gly Trp Glu Leu Glu Leu Cys Val Gly Gln 85 90 95 Thr Gly Gly Val
Pro Arg Leu Gly Val Pro Gly Met Cys Leu Gln Asp 100 105 110 Ser Pro
Leu Gly Val Arg Asp Ser Asp Tyr Asn Ser Ala Phe Pro Ala 115 120 125
Gly Met Asn Val Ala Ala Thr Trp Asp Lys Asn Leu Ala Tyr Leu Arg 130
135 140 Gly Lys Ala Met Gly Gln Glu Phe Ser Asp Lys Gly Ala Asp Ile
Gln 145 150 155 160 Leu Gly Pro Ala Ala Gly Pro Leu Gly Arg Ser Pro
Asp Gly Gly Arg 165 170 175 Asn Trp Glu Gly Phe Ser Pro Asp Pro Ala
Leu Ser Gly Val Leu Phe 180 185 190 Ala Glu Thr Ile Lys Gly Ile Gln
Asp Ala Gly Val Val Ala Thr Ala 195 200 205 Lys His Tyr Ile Ala Tyr
Glu Gln Glu His Phe Arg Gln Ala Pro Glu 210 215 220 Ala Gln Gly Phe
Gly Phe Asn Ile Ser Glu Ser Gly Ser Ala Asn Leu 225 230 235 240 Asp
Asp Lys Thr Met His Glu Leu Tyr Leu Trp Pro Phe Ala Asp Ala 245 250
255 Ile Arg Ala Gly Ala Gly Ala Val Met Cys Ser Tyr Asn Gln Ile Asn
260 265 270 Asn Ser Tyr Gly Cys Gln Asn Ser Tyr Thr Leu Asn Lys Leu
Leu Lys 275 280 285 Ala Glu Leu Gly Phe Gln Gly Phe Val Met Ser Asp
Trp Ala Ala His 290 295 300 His Ala Gly Val Ser Gly Ala Leu Ala Gly
Leu Asp Met Ser Met Pro 305 310 315 320 Gly Asp Val Asp Tyr Asp Ser
Gly Thr Ser Tyr Trp Gly Thr Asn Leu 325 330 335 Thr Ile Ser Val Leu
Asn Gly Thr Val Pro Gln Trp Arg Val Asp Asp 340 345 350 Met Ala Val
Arg Ile Met Ala Ala Tyr Tyr Lys Val Gly Arg Asp Arg 355 360 365 Leu
Trp Thr Pro Pro Asn Phe Ser Ser Trp Thr Arg Asp Glu Tyr Gly 370 375
380 Tyr Lys Tyr Tyr Tyr Val Ser Glu Gly Pro Tyr Glu Lys Val Asn Gln
385 390 395 400 Tyr Val Asn Val Gln Arg Asn His Ser Glu Leu Ile Arg
Arg Ile Gly 405 410 415 Ala Asp Ser Thr Val Leu Leu Lys Asn Asp Gly
Ala Leu Pro Leu Thr 420 425 430 Gly Lys Glu Arg Leu Val Ala Leu Ile
Gly Glu Asp Ala Gly Ser Asn 435 440 445 Pro Tyr Gly Ala Asn Gly Cys
Ser Asp Arg Gly Cys Asp Asn Gly Thr 450 455 460 Leu Ala Met Gly Trp
Gly Ser Gly Thr Ala Asn Phe Pro Tyr Leu Val 465 470 475 480 Thr Pro
Glu Gln Ala Ile Ser Asn Glu Val Leu Lys His Lys Asn Gly 485 490 495
Val Phe Thr Ala Thr Asp Asn Trp Ala Ile Asp Gln Ile Glu Ala Leu 500
505 510 Ala Lys Thr Ala Ser Val Ser Leu Val Phe Val Asn Ala Asp Ser
Gly 515 520 525 Glu Gly Tyr Ile Asn Val Asp Gly Asn Leu Gly Asp Arg
Arg Asn Leu 530 535 540 Thr Leu Trp Arg Asn Gly Asp Asn Val Ile Lys
Ala Ala Ala Ser Asn 545 550 555 560 Cys Asn Asn Thr Ile Val Val Ile
His Ser Val Gly Pro Val Leu Val 565 570 575 Asn Glu Trp Tyr Asp Asn
Pro Asn Val Thr Ala Ile Leu Trp Gly Gly 580 585 590 Leu Pro Gly Gln
Glu Ser Gly Asn Ser Leu Ala Asp Val Leu Tyr Gly 595 600 605 Arg Val
Asn Pro Gly Ala Lys Ser Pro Phe Thr Trp Gly Lys Thr Arg 610 615 620
Glu Ala Tyr Gln Asp Tyr Leu Val Thr Glu Pro Asn Asn Gly Asn Gly 625
630 635 640 Ala Pro Gln Glu Asp Phe Val Glu Gly Val Phe Ile Asp Tyr
Arg Gly 645 650 655 Phe Asp Lys Arg Asn Glu Thr Pro Ile Tyr Glu Phe
Gly Tyr Gly Leu 660 665 670 Ser Tyr Thr Thr Phe Asn Tyr Ser Asn Leu
Glu Val Gln Val Leu Ser 675 680 685 Ala Pro Ala Tyr Glu Pro Ala Ser
Gly Glu Thr Glu Ala Ala Pro Thr 690 695 700 Phe Gly Glu Val Gly Asn
Ala Ser Asp Tyr Leu Tyr Pro Ser Gly Leu 705 710 715 720 Leu Arg Ile
Thr Lys Phe Ile Tyr Pro Trp Leu Asn Gly Thr Asp Leu 725 730 735 Glu
Ala Ser Ser Gly Asp Ala Ser Tyr Gly Gln Asp Ser Ser Asp Tyr 740 745
750 Leu Pro Glu Gly Ala Thr Asp Gly Ser Ala Gln Pro Ile Leu Pro Ala
755 760 765 Gly Gly Gly Pro Gly Gly Asn Pro Arg Leu Tyr Asp Glu Leu
Ile Arg 770 775 780 Val Ser Val Thr Ile Lys Asn Thr Gly Lys Val Ala
Gly Asp Glu Val 785 790 795 800 Pro Gln Leu Tyr Val Ser Leu Gly Gly
Pro Asn Glu Pro Lys Ile Val 805 810 815 Leu Arg Gln Phe Glu Arg Ile
Thr Leu Gln Pro Ser Glu Glu Thr Lys 820 825 830 Trp Ser Thr Thr Leu
Thr Arg Arg Asp Leu Ala Asn Trp Asn Val Glu 835 840 845 Lys Gln Asp
Trp Glu Ile Thr Ser Tyr Pro Lys Met Val Phe Val Gly 850 855 860 Ser
Ser Ser Arg Lys Leu Pro Leu Arg Ala Ser Leu Pro Thr Val His 865 870
875 880 Asp Glu Leu 20 23 DNA Artificial sequence Single strand DNA
oligonucleotide 20 cagtgaccgt ggatgcgaca atg 23 21 40 DNA
Artificial sequence Single strand DNA oligonucleotide 21 agagacggat
gacaagtact acttgaaatt gggcccaaaa 40 22 23 DNA Artificial sequence
Single strand DNA oligonucleotide 22 cagtgaccgt ggatgcgaca atg 23
23 33 DNA Artificial sequence Single strand DNA oligonucleotide 23
aaaggatcct tagtgaacag taggcagaga cgc 33 24 4 PRT Artificial
sequence ER retaining signal peptide 24 Lys Asp Glu Leu 1
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