U.S. patent application number 12/322782 was filed with the patent office on 2009-09-10 for polypeptide having activity of aminoacyl-trna synthetase and use thereof.
This patent application is currently assigned to RIKEN. Invention is credited to Takahito Mukai, Kenji Oki, Kensaku Sakamoto, Shigeyuki Yokoyama.
Application Number | 20090226966 12/322782 |
Document ID | / |
Family ID | 41054004 |
Filed Date | 2009-09-10 |
United States Patent
Application |
20090226966 |
Kind Code |
A1 |
Yokoyama; Shigeyuki ; et
al. |
September 10, 2009 |
Polypeptide having activity of aminoacyl-tRNA synthetase and use
thereof
Abstract
A polypeptide according to the present invention includes: an
altered polypeptide obtained by altering an ArgRS, a CysRS, a
MetRS, a GlnRS, a GluRS, a LysRS, a TyrRS, or a TrpRS so that an
unnatural amino acid is recognized; and an editing polypeptide
derived from a PheRS, a LeuRS, an IleRS, a ValRS, an AlaRS, a
ProRS, or a ThrRS, the editing polypeptide having been either
inserted between a Rossman-fold N domain and a Rossman-fold C
domain that exist in the altered polypeptide, or bound to an N
terminal of the altered polypeptide. Thus provided are a new aaRS
that exhibits high substrate specificity to an unnatural amino acid
and a technique that involves the use of such an aaRS.
Inventors: |
Yokoyama; Shigeyuki;
(Yokohama-Shi, JP) ; Sakamoto; Kensaku;
(Yokohama-Shi, JP) ; Oki; Kenji; (Yokohama-Shi,
JP) ; Mukai; Takahito; (Yokohama-Shi, JP) |
Correspondence
Address: |
EDWARDS ANGELL PALMER & DODGE LLP
P.O. BOX 55874
BOSTON
MA
02205
US
|
Assignee: |
RIKEN
Saitama
JP
|
Family ID: |
41054004 |
Appl. No.: |
12/322782 |
Filed: |
February 5, 2009 |
Current U.S.
Class: |
435/69.1 ;
435/183; 536/23.2 |
Current CPC
Class: |
C12N 9/93 20130101 |
Class at
Publication: |
435/69.1 ;
435/183; 536/23.2 |
International
Class: |
C12N 9/00 20060101
C12N009/00; C12N 15/52 20060101 C12N015/52; C12P 21/02 20060101
C12P021/02 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 8, 2008 |
JP |
29236/2008 |
Claims
1. A polypeptide having aminoacyl-tRNA synthetase activity, the
polypeptide comprising: an altered polypeptide obtained by altering
an arginyl-tRNA synthetase, a cysteinyl-tRNA synthetase, a
methionyl-tRNA synthetase, a glutaminyl-tRNA synthetase, a
glutamyl-tRNA synthetase, a lysyl-tRNA synthetase, a tyrosyl-tRNA
synthetase, or a tryptophanyl-tRNA synthetase so that an unnatural
amino acid is recognized; and an editing polypeptide containing an
editing reaction active site derived from a phenylalanyl-tRNA
synthetase, a leucyl-tRNA synthetase, an isoleucyl-tRNA synthetase,
a valyl-tRNA synthetase, an alanyl-tRNA synthetase, a prolyl-tRNA
synthetase, or a threonyl-tRNA synthetase, the editing polypeptide
having been either inserted between a Rossman-fold N domain and a
Rossman-fold C domain that exist in the altered polypeptide, or
bound to an N terminal of the altered polypeptide.
2. The polypeptide as set forth in claim 1, wherein the editing
polypeptide has been inserted into a CP1 domain that lies between
the Rossman-fold N domain and the Rossman-fold C domain.
3. The polypeptide as set forth in claim 1, wherein a linker
polypeptide that connects the editing polypeptide with the altered
polypeptide has been further inserted.
4. The polypeptide as set forth in claim 1, wherein the altered
polypeptide is a tyrosyl-tRNA synthetase altered so as to recognize
an unnatural amino acid.
5. The polypeptide as set forth in claim 1, wherein the
tyrosyl-tRNA synthetase is derived from eukaryotic organisms or
eubacteria.
6. The polypeptide as set forth in claim 5, wherein the eubacteria
are Escherichia coli.
7. The polypeptide as set forth in claim 1, wherein the
tyrosyl-tRNA synthetase is a polypeptide altered so as to recognize
a tyrosine derivative.
8. The polypeptide as set forth in claim 7, wherein the tyrosine
derivative is 3-iodotyrosine.
9. The polypeptide as set forth in claim 1, wherein the altered
polypeptide is a polypeptide as set forth in either of (a) and (b):
(a) a polypeptide consisting of an amino-acid sequence represented
by SEQ ID NO: 1; and (b) a polypeptide (i) consisting of an
amino-acid sequence, represented by SEQ ID NO: 1 with a deletion,
insertion, substitution, or addition of one or several amino acids
and (ii) having activity to bind 3-iodotyrosine to tRNA.
10. The polypeptide as set forth in claim 1, wherein the editing
polypeptide is derived from a phenylalanyl-tRNA synthetase.
11. The polypeptide as set forth in claim 1, wherein the
phenylalanyl-tRNA synthetase is derived from eukaryotic organisms
or archaebacteria.
12. The polypeptide as set forth in claim 11, wherein the
archaebacteria belong to the genus Pyrococcus.
13. The polypeptide as set forth in claim 11, wherein the
archaebacteria are Pyrococcus horikoshii.
14. The polypeptide as set forth in claim 1, wherein the editing
polypeptide is a polypeptide as set forth in either of (c) and (d):
(c) a polypeptide consisting of an amino-acid sequence represented
by SEQ ID NO: 2; and (d) a polypeptide (i) consisting of an
amino-acid sequence, represented by SEQ ID NO: 2 with a deletion,
insertion, substitution, or addition of one or several amino acids
and (ii) having activity to degrade binding of tyrosine to tRNA or
activity to degrade tyrosyl adenylate intermediate into tyrosine
and an inorganic phosphoric acid.
15. The polypeptide as set forth in claim 1, wherein the
polypeptide is a polypeptide as set forth in either of (e) and (f):
(e) a polypeptide consisting of an amino-acid sequence represented
by SEQ ID NO: 3; and (f) a polypeptide (i) consisting of an
amino-acid sequence, represented by SEQ ID NO: 3 with a deletion,
insertion, substitution, or addition of one or several amino acids
and (ii) having activity to degrade binding of tyrosine to tRNA or
activity to degrade tyrosyl adenylate intermediate into tyrosine
and an inorganic phosphoric acid and activity to bind an unnatural
amino acid to tRNA.
16. The polypeptide as set forth in claim 1, wherein: the altered
polypeptide is a tyrosyl-tRNA synthetase altered so as to recognize
an unnatural amino acid and the editing polypeptide contains an
editing reaction active site derived from a phenylalanyl-tRNA
synthetase; or the altered polypeptide is a methionyl-tRNA
synthetase altered so as to recognize an unnatural amino acid and
the editing polypeptide contains an editing reaction active site
derived from a leucyl-tRNA synthetase.
17. A polynucleotide coding for a polypeptide having aminoacyl-tRNA
synthetase activity as set froth in claim 1.
18. A method for producing a polypeptide having aminoacyl-tRNA
synthetase activity, the method comprising: a preparing step of
preparing a polynucleotide in which a polynucleotide coding for an
editing polypeptide containing an editing reaction active site
derived from a phenylalanyl-tRNA synthetase, a leucyl-tRNA
synthetase, an isoleucyl-tRNA synthetase, a valyl-tRNA synthetase,
an alanyl-tRNA synthetase, a prolyl-tRNA synthetase, or a
threonyl-tRNA synthetase has been introduced into a polynucleotide
coding for an altered polypeptide obtained by altering an
arginyl-tRNA synthetase, a cysteinyl-tRNA synthetase, a
methionyl-tRNA synthetase, a glutaminyl-tRNA synthetase, a
glutamyl-tRNA synthetase, a lysyl-tRNA synthetase, a tyrosyl-tRNA
synthetase, or a tryptophanyl-tRNA synthetase so that an unnatural
amino acid is recognized; and an expressing step of expressing a
polypeptide coded for by the polynucleotide obtained in the
preparing step, the preparing step includes preparing either a
polynucleotide in which the editing polypeptide has been introduced
so as to be positioned between a Rossman-fold N domain and a
Rossman-fold C domain that exist in the altered polypeptide, or a
polynucleotide in which the editing polypeptide has been introduced
so as to be bound to an N terminal of the altered polypeptide.
Description
[0001] This Nonprovisional application claims priority under U.S.C.
.sctn. 119(a) on Patent Application No. 029236/2008 filed in Japan
on Feb. 8, 2008, the entire contents of which are hereby
incorporated by reference.
FIELD OF THE INVENTION
[0002] The present invention relates to polypeptides having
aminoacyl-tRNA synthetase activity and use thereof. More
specifically, the present invention relates to a polypeptide having
aminoacyl-tRNA synthetase activity that exhibits high specificity
of association between an unnatural amino acid and tRNA and use
thereof.
BACKGROUND OF THE INVENTION
[0003] In recent years, the development of genetic engineering and
the resulting sufficiency of information on three-dimensional
protein structures, genome sequences, and the like have made it
possible to create a protein with a new function by artificially
altering a protein or, specifically, to create a protein with new
activity by altering, based on a protein having certain activity,
some amino-acid residues of the protein. For alteration of
amino-acid residues to other amino-acid residues, natural amino
acids are limited as options, and as such, may make it difficult to
produce a protein having a desired function and desired
activity.
[0004] Proposed in view of this as a method for expanding the
functions of a protein are various methods that involves the
introduction of an unnatural amino acid into a protein (e.g., see
Wang, L., and Schultz, P. G., Expanding the genetic code. Angew
Chem Int Ed Engl, 2005, 44, 34-66.). Among them, a method that
involves the use of an aminoacyl-tRNA synthetase (hereinafter
referred to sometimes as "aaRS") mutant has recently been developed
as a method that can be used in living cells with high yields
(International Publication No. 2003/014354 Pamphlet (published on
Feb. 20, 2003), Lee, N., Bessho, Y., Wei, K., Szostak, J. W., and
Suga, H., Ribozyme-catalyzed tRNA aminoacylation. Nat Struct Biol,
2000, 7, 28-33.).
[0005] An aaRS exists in all living organisms. An aaRS is
responsible for faithfully translating a genetic code by accurately
associating an amino acid with tRNA. A reaction catalyzed by an
aaRS includes a first step of activating an amino acid with ATP and
a second step of adding an activated aminoacyl adenylate
intermediate to the 3'-end of tRNA. Both of the reactions are
carried out at a single active site (aminoacylation active site)
(Fersht, A. R., and Kaethner, M. M., Mechanism of aminoacylation of
tRNA. Proof of the aminoacyl adenylate pathway for the isoleucyl-
and tyrosyl-tRNA synthetases from Escherichia coli K12.
Biochemistry, 1976, 15, 818-823; and Freist, W., and Sternbach, H.,
Tyrosyl-tRNA synthetase from baker's yeast. Order of substrate
addition, discrimination of 20 amino acids in aminoacylation of
tRNATyr-C-C-A and tRNATyr-C-C-A(3'NH.sub.2). Eur J Biochem, 1988,
177, 425-433.).
[0006] There are two classes of aaRS, each with its own origin of
evolution, and each of the classes includes 10 aaRSs (Eriani, G.,
Delarue, M., Poch, O., Gangloff, J., and Moras, D., Partition of
tRNA synthetases into two classes based on mutually exclusive sets
of sequence motifs. Nature, 1990, 347, 203-206.). A class I aaRS
has an aminoacylation active site called a Rossman-fold domain.
Meanwhile, a class II aaRSs does not have a Rossman-fold domain,
but has an aminoacylation active site surrounded by an antiparallel
beta-sheet. An aaRS must associate an amino acid with tRNA
accurately. tRNAs are large molecules whose molecular weight
exceeds 20,000, and vary in sequence. Meanwhile, amino acids are
small molecules that share an .alpha.-amino group and an
.alpha.-carboxyl group as common structures, and differ only in
side chain. This makes it more difficult for an aaRS to
discriminate between amino acids than to discriminate between
tRNAs. For example, isoleucine and valine differ solely in methyl
group, and it is believed to be difficult for an enzyme to
recognize the difference (Pauling, L., The Probability of Errors in
the Process of Synthesis of Protein Molecules, 1957.).
[0007] For this reason, each of seven types of natural aaRS, which
amount to one third of all the natural aaRSs, namely an
isoleucyl-tRNA synthetase (hereinafter referred to as "IleRS") of
class I, a valyl-tRNA synthetase (hereinafter referred to as
"ValRS") of class I, a leucyl-tRNA synthetase (hereinafter referred
to as "LeuRS") of class I, an alanyl-tRNA synthetase (hereinafter
referred to as "AlaRS") of class II, a prolyl-tRNA synthetase
(hereinafter referred to as "ProRS") of class II, a threonyl-tRNA
synthetase (hereinafter referred to as "ThrRS") of class II, and a
phenylalanyl-tRNA synthetase (hereinafter referred to as "PheRS")
of class II, is known to have an aminoacylation active site,
serving as an active site, which not only recognizes a correct
substrate amino acid but also misrecognizes another amino acid
similar the correct substrate amino acid (Crepin, T., Yaremchuk,
A., Tukalo, M., and Cusack, S., Structures of two bacterial
prolyl-tRNA synthetases with and without a cis-editing domain.
Structure, 2006, 14, 1511-1525.; Dock-Bregeon, A.,
Sankaranarayanan, R., Romby, P., Caillet, J., Springer, M., Rees,
B., Francklyn, C. S., Ehresmann, C., and Moras, D., Transfer
RNA-mediated editing in threonyl-tRNA synthetase. The class II
solution to the double discrimination problem. Cell, 2000, 103,
877-884.; Fukai, S., Nureki, O., Sekine, S., Shimada, A., Tao, J.,
Vassylyev, D. G., and Yokoyama, S., Structural basis for
double-sieve discrimination of L-valine from L-isoleucine and
L-threonine by the complex of tRNA (Val) and valyl-tRNA synthetase.
Cell, 2000, 103, 793-803.; Fukunaga, R., and Yokoyama, S.,
Aminoacylation complex structures of leucyl-tRNA synthetase and
tRNALeu reveal two modes of discriminator-base recognition. Nat
Struct Mol Biol, 2005, 12, 915-922.; Lin, L., Hale, S. P., and
Schimmel, P., Aminoacylation error correction. Nature, 1996, 384,
33-34.; Nomanbhoy, T. K., Hendrickson, T. L., and Schimmel, P.,
Transfer RNA-dependent translocation of misactivated amino acids to
prevent errors in protein synthesis. Mol Cell, 1999 4, 519-528.;
Nureki, O., Vassylyev, D. G., Tateno, M., Shimada, A., Nakama, T.,
Fukai, S., Konno, M., Hendrickson, T. L., Schimmel, P., and
Yokoyama, S., Enzyme structure with two catalytic sites for
double-sieve selection of substrate. Science, 1998, 280, 578-582.;
Roy, H., Ling, J., Irnov, M., and Ibba, M., Post-transfer editing
in vitro and in vivo by the beta subunit of phenylalanyl-tRNA
synthetase. EMBO J, 2004, 23, 4639-4648.; Ruan, B., and Soll, D.,
The bacterial YbaK protein is a Cys-tRNAPro and Cys-tRNA Cys
deacylase. J Biol Chem, 2005, 280, 25887-25891.; Sokabe, M., Okada,
A., Yao, M., Nakashima, T., and Tanaka, I., Molecular basis of
alanine discrimination in editing site. Proc Natl Acad Sci USA,
2005, 102, 11669-11674.; and Swairjo, M. A., Otero, F. J., Yang, X.
L., Lovato, M. A., Skene, R. J., McRee, D. E., Ribas de Pouplana,
L., and Schimmel, P., Alanyl-tRNA synthetase crystal structure and
design for acceptor-stem recognition. Mol Cell, 2004, 13,
829-841.). As a result of such misrecognition, an aminoacyl
adenylate intermediate is produced by activation with an amino acid
different from the correct substrate, or aminoacyl tRNA is produced
as a product thereof.
[0008] However, each of these aaRSs has an editing reaction active
site separately from the aminoacylation active site, and as such,
has activity to degrade the mistakenly produced aminoacyl adenylate
intermediate into an amino acid and an inorganic phosphoric acid or
activity to degrade aminoacyl tRNA into an amino acid and tRNA. The
editing reaction active site exists in a domain independent of a
domain containing the aminoacylation active site (Fukai, S. et.
al., Cell, 2000, 103, 793-803.; Fukunaga, R., and Yokoyama, S., Nat
Struct Mol Biol, 2005, 12, 915-922.; Nureki, O. et. al., Science,
1998, 280, 578-582.; Kotik-Kogan, O., Moor, N., Tworowski, D., and
Safro, M., Structural basis for discrimination of L-phenylalanine
from L-tyrosine by phenylalanyl-tRNA synthetase. Structure, 2005,
13, 1799-1807.; and Ribas de Pouplana, L., and Schimmel, P., Two
classes of tRNA synthetases suggested by sterically compatible
dockings on tRNA acceptor stem. Cell, 2001, 104, 191-193.). The
domain is called an editing reaction domain. Specifically, each of
these aaRSs strictly recognizes only a single amino acid by
recognizing the separate properties (size, hydrophilicity,
hydrophobicity) of an amino-acid side chain by the two reaction
sites (Fukai, S. et. al., Cell, 2000, 103, 793-803.).
[0009] It should be noted that each of the aaRSs other than the
aforementioned seven types of aaRS each of which has an editing
reaction active site does not have an editing reaction site, and as
such, recognizes a single amino acid only by an aminoacylation
active site (Fersht, A. R., Shindler, J. S., and Tsui, W. C.,
Probing the limits of protein-amino acid side chain recognition
with the aminoacyl-tRNA synthetases. Discrimination against
phenylalanine by tyrosyl-tRNA synthetases. Biochemistry, 1980 19,
5520-5524.).
[0010] Incidentally, an aaRS mutant is produced by substituting an
amino-acid residue of a substrate recognition site of a wild-type
aaRS. For example, TyrRS is the first aaRS that succeeded in
alteration for introduction of an unnatural amino acid. Further,
TyrRS has a large amino-acid-binding pocket for recognizing a
comparatively large amino acid, tyrosine, and presently has the
largest number of mutants specific to unnatural amino acids
(International Publication No. 2003/014354 Pamphlet; and Wang, L.,
Xie, J., and Schultz, P. G., Expanding the genetic code. Annu Rev
Biophys Biomol Struct, 2006, 35, 225-249.). For example, there has
been a report on a tyrosyl-tRNA synthetase (hereinafter referred to
as "TyrRS") mutant. Specifically, in International Publication No.
2003/014354 Pamphlet, known examples of a mutant that recognizes
3-iodotyrosine, which is an unnatural amino acid, include an
Escherichia coli-derived TyrRS mutant and a Methanocaldococcus
jannaschii-derived TyrRS mutant (MjIYRS).
SUMMARY OF THE INVENTION
[0011] As mentioned above, aaRS mutants that specifically recognize
unnatural amino acids have been produced so far. However, the
substrate specificity of such an aaRS mutant to an unnatural amino
acid is not sufficient. Therefore, there has been a demand for the
development of a new aaRS mutant.
[0012] It is an object of the present invention to provide a new
aaRS that exhibits high specificity to an amino acid to be
recognized and a technique that involves the use of such an
aaRS.
[0013] In order to attain the foregoing object, the inventors
diligently studied. As a result, the inventors newly found that by
binding an aaRS-derived editing polypeptide having an editing
reaction active site to a specific domain in an altered polypeptide
obtained by so altering a class I aaRS having no editing reaction
active site that an unnatural amino acid is recognized, the altered
polypeptide is made to exhibit editing reaction activity without
losing its function of recognizing an unnatural amino acid. The
present invention, based on the new findings, encompasses the
following inventions.
[0014] That is, in order to attain the foregoing object, a
polypeptide according to the present invention is a polypeptide
having aminoacyl-tRNA synthetase activity, the polypeptide
including: an altered polypeptide obtained by altering an
arginyl-tRNA synthetase, a cysteinyl-tRNA synthetase, a
methionyl-tRNA synthetase, a glutaminyl-tRNA synthetase, a
glutamyl-tRNA synthetase, a lysyl-tRNA synthetase, a tyrosyl-tRNA
synthetase, or a tryptophanyl-tRNA synthetase so that an unnatural
amino acid is recognized; and an editing polypeptide containing an
editing reaction active site derived from a phenylalanyl-tRNA
synthetase, a leucyl-tRNA synthetase, an isoleucyl-tRNA synthetase,
a valyl-tRNA synthetase, an alanyl-tRNA synthetase, a prolyl-tRNA
synthetase, or a threonyl-tRNA synthetase, the editing polypeptide
having been either inserted between a Rossman-fold N domain and a
Rossman-fold C domain that exist in the altered polypeptide, or
bound to an N terminal of the altered polypeptide.
[0015] In the polypeptide according to the present invention, it is
more preferable that the editing polypeptide have been inserted
into a CP1 domain, had by the altered polypeptide, which lies
between the Rossman-fold N domain and the Rossman-fold C
domain.
[0016] In the polypeptide according to the present invention, it is
more preferable that a linker polypeptide that connects the editing
polypeptide with the altered polypeptide have been further
inserted.
[0017] In the polypeptide according to the present invention, the
altered polypeptide may be a tyrosyl-tRNA synthetase altered so as
to recognize an unnatural amino acid.
[0018] In the polypeptide according to the present invention, it is
more preferable that the tyrosyl-tRNA synthetase be derived from
eukaryotic organisms or eubacteria.
[0019] In the polypeptide according to the present invention, it is
more preferable that the eubacteria be Escherichia coli.
[0020] In the polypeptide according to the present invention, the
tyrosyl-tRNA synthetase may be a polypeptide altered so as to
recognize a tyrosine derivative.
[0021] In the polypeptide according to the present invention, the
tyrosine derivative may be 3-iodotyrosine.
[0022] In the polypeptide according to the present invention, it is
more preferable that the altered polypeptide be a polypeptide as
set forth in either of (a) and (b): (a) a polypeptide consisting of
an amino-acid sequence represented by SEQ ID NO: 1; and (b) a
polypeptide (i) consisting of an amino-acid sequence, represented
by SEQ ID NO: 1 with a deletion, insertion, substitution, or
addition of one or several amino acids and (ii) having activity to
bind 3-iodotyrosine to tRNA.
[0023] In the polypeptide according to the present invention, the
editing polypeptide may be derived from a phenylalanyl-tRNA
synthetase.
[0024] In the polypeptide according to the present invention, it is
more preferable that the phenylalanyl-tRNA synthetase be derived
from eukaryotic organisms or archaebacteria.
[0025] In the polypeptide according to the present invention, it is
more preferable that the archaebacteria belong to the genus
Pyrococcus.
[0026] In the polypeptide according to the present invention, it is
more preferable that the archaebacteria be Pyrococcus
horikoshii.
[0027] In the polypeptide according to the present invention, it is
more preferable that the editing polypeptide be a polypeptide as
set forth in either of (c) and (d): (c) a polypeptide consisting of
an amino-acid sequence represented by SEQ ID NO: 2; and (d) a
polypeptide (i) consisting of an amino-acid sequence, represented
by SEQ ID NO: 2 with a deletion, insertion, substitution, or
addition of one or several amino acids and (ii) having activity to
degrade binding of tyrosine to tRNA or activity to degrade tyrosyl
adenylate intermediate into tyrosine and an inorganic phosphoric
acid.
[0028] It is more preferable that the polypeptide according to the
present invention be a polypeptide as set forth in either of (e)
and (f): (e) a polypeptide consisting of an amino-acid sequence
represented by SEQ ID NO: 3; and (f) a polypeptide (i) consisting
of an amino-acid sequence, represented by SEQ ID NO: 3 with a
deletion, insertion, substitution, or addition of one or several
amino acids and (ii) having activity to degrade binding of tyrosine
to tRNA or activity to degrade tyrosyl adenylate intermediate into
tyrosine and an inorganic phosphoric acid and activity to bind an
unnatural amino acid to tRNA.
[0029] In the polypeptide according to the present invention, it is
more preferable that: the altered polypeptide be a tyrosyl-tRNA
synthetase altered so as to recognize an unnatural amino acid and
the editing polypeptide contain an editing reaction active site
derived from a phenylalanyl-tRNA synthetase; or the altered
polypeptide be a methionyl-tRNA synthetase altered so as to
recognize an unnatural amino acid and the editing polypeptide
contain an editing reaction active site derived from a leucyl-tRNA
synthetase.
[0030] Further, the present invention encompasses a polynucleotide
coding for the polypeptide according to the present invention.
[0031] Further, a production method according to the present
invention is a method for producing a polypeptide having
aminoacyl-tRNA synthetase activity, the method including: a
preparing step of preparing a polynucleotide in which a
polynucleotide coding for an editing polypeptide containing an
editing reaction active site derived from a phenylalanyl-tRNA
synthetase, a leucyl-tRNA synthetase, an isoleucyl-tRNA synthetase,
a valyl-tRNA synthetase, an alanyl-tRNA synthetase, a prolyl-tRNA
synthetase, or a threonyl-tRNA synthetase has been introduced into
a polynucleotide coding for an altered polypeptide obtained by
altering an arginyl-tRNA synthetase, a cysteinyl-tRNA synthetase, a
methionyl-tRNA synthetase, a glutaminyl-tRNA synthetase, a
glutamyl-tRNA synthetase, a lysyl-tRNA synthetase, a tyrosyl-tRNA
synthetase, or a tryptophanyl-tRNA synthetase so that an unnatural
amino acid is recognized; and an expressing step of expressing a
polypeptide coded for by the polynucleotide obtained in the
preparing step, the preparing step includes preparing either a
polynucleotide in which the editing polypeptide has been introduced
so as to be positioned between a Rossman-fold N domain and a
Rossman-fold C domain that exist in the altered polypeptide, or a
polynucleotide in which the editing polypeptide has been introduced
so as to be bound to an N terminal of the altered polypeptide.
[0032] Additional objects, features, and strengths of the present
invention will be made clear by the description below. Further, the
advantages of the present invention will be evident from the
following explanation in reference to the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0033] FIG. 1, showing an embodiment of the present invention,
shows the hydrolysis activity of editing reaction peptides.
[0034] FIG. 2, showing an embodiment of the present invention,
schematically shows the structures of fusion proteins.
[0035] FIG. 3, showing an embodiment of the present invention,
shows the hydrolysis activity of fusion proteins.
[0036] FIG. 4, showing an embodiment of the present invention,
shows the substrate recognition specificity of fusion proteins.
[0037] FIG. 5, showing an embodiment of the present invention,
shows the hydrolysis activity of fusion proteins.
[0038] FIG. 6, showing an embodiment of the present invention,
shows the substrate recognition specificity of fusion proteins.
[0039] FIG. 7, showing an embodiment of the present invention,
shows the hydrolysis activity of fusion proteins.
[0040] FIG. 8, showing an embodiment of the present invention, is a
western blotting diagram showing the results of protein synthesis
in a cell-free translation system with use of fusion proteins.
[0041] FIG. 9, showing an embodiment of the present invention, is a
western blotting diagram showing the results of protein synthesis
in cultured mammalian cells with use of fusion proteins.
DESCRIPTION OF THE EMBODIMENTS
1. Polypeptide According to the Present Invention
[0042] A polypeptide according to the present invention only needs
to be a polypeptide having aminoacyl-tRNA synthetase activity, the
polypeptide including: an altered polypeptide obtained by altering
an arginyl-tRNA synthetase (hereinafter referred to as "ArgRS"), a
cysteinyl-tRNA synthetase (hereinafter referred to as "CysRS"), a
methionyl-tRNA synthetase (hereinafter referred to as "MetRS"), a
glutaminyl-tRNA synthetase (hereinafter referred to as "GlnRS"), a
glutamyl-tRNA synthetase (hereinafter referred to as "GluRS"), a
lysyl-tRNA synthetase (hereinafter referred to as "LysRS"), a
tyrosyl-tRNA synthetase (hereinafter referred to as "TyrRS"), or a
tryptophanyl-tRNA synthetase (hereinafter referred to as "TrpRS")
so that an unnatural amino acid is recognized; and an editing
polypeptide derived from a PheRS, a LeuRS, an IleRS, a ValRS, an
AlaRS, a ProRS, or a ThrRS, the editing polypeptide having been
either inserted between a Rossman-fold N domain and a Rossman-fold
C domain that exist in the altered polypeptide, or bound to an N
terminal of the altered polypeptide.
[0043] This makes it possible to obtain an aaRS that exhibits
excellent substrate specificity. For example, in order to cause a
substrate for the tyrosyl-tRNA synthetase to be an unnatural amino
acid (e.g., 3-iodotyrosine) other than tyrosine, it is necessary to
alter the amino-acid recognition domain of the TyrRS. Depending on
how the domain is altered, the domain may recognize an amino acid
other than the unnatural amino acid after alteration. However, the
polypeptide according to the present invention has the editing
polypeptide. Moreover, the editing polypeptide has been either
inserted between the Rossman-fold N domain and the Rossman-fold C
domain, or bound to the N terminal of the altered polypeptide.
Therefore, the editing polypeptide functions effectively. That is,
even in the case of misrecognition of an amino acid, such
misrecognition can be corrected by the editing polypeptide. This
makes it possible to obtain an aminoacyl-tRNA synthetase that
exhibits high specificity of association between an unnatural amino
acid and tRNA.
[0044] In this specification, the "polypeptide having
aminoacyl-tRNA synthetase activity" means a polypeptide having the
aminoacyl-tRNA synthesis activity of an aminoacyl-tRNA synthetase.
The "aminoacyl-tRNA synthesis activity" means activity that
synthesizes aminoacyl-tRNA by binding an amino acid to tRNA.
[0045] Further, the "unnatural amino acid" means an amino acid
other than amino acids genetically encoded by natural living
organisms. It should be noted that the "amino acids genetically
encoded" mean 22 types of amino acid, namely 20 types of standard
amino acid universally used by living organisms, selenomethionine,
and pyrrolidine.
[0046] Further, examples of the unnatural amino acid include:
3-halogen-substituted tyrosine such as 3-iodotyrosine,
3-hydroxytyrosine, and 3-azidotyrosine, each having a substituent
at the 3-position of tyrosine; parabenzoylphenylalanine, and
4-iodophenylalanine, 4-azidophenylalanine, each having a
substituent at the 4-position of phenylalanine; and the like.
[0047] [1-1. Altered Polypeptide]
[0048] In this specification, the "altered polypeptide" only needs
to be a polypeptide obtained by altering an ArgRS, a CysRS, a
MetRS, a GlnRS, a GluRS, a LysRS, a TyrRS, or a TrpRS so that an
unnatural amino acid is recognized.
[0049] The ArgRS, the CysRS, the MetRS, the GlnRS, the GluRS, the
LysRS, the TyrRS, and the TrpRS are not particularly limited, but
are preferably derived from eubacteria such as Escherichia coli and
heat-resistant bacteria, archaebacteria or eukaryotic organisms
such as yeasts, animals, and plants, or in particular, from
Escherichia coli or archaebacteria.
[0050] An aaRS derived from archaebacteria is not used in the cells
of eukaryotic organisms to synthesize a protein containing an
unnatural amino acid, but can be used in the cells of prokaryotic
organisms. Therefore, an altered polypeptide obtained with use of
an aaRS derived from archaebacteria can be used in the cells of
prokaryotic organisms or in cell-free translation systems derived
from prokaryotic organisms.
[0051] Further, an aaRS derived from Escherichia coli cannot be
used in the cells of prokaryotic organisms, but functions in the
cells of eukaryotic organisms (yeast cells, plant cells, insect
cells, and mammalian cells), and as such, is used to synthesize a
protein containing an unnatural amino acid. Therefore, an altered
polypeptide obtained with use of an aaRS derived from Escherichia
coli can be used for protein synthesis in the cells of eukaryotic
organisms or in cell-free translations system derived from
eukaryotic organisms.
[0052] There is no particular limit on how to obtain an ArgRS or
the like from such a living organism as mentioned above. However,
for example, based on the following conventional publicly-known
base sequences and the like, it is possible to obtain, by a
nucleic-acid amplification reaction such as PCR, a polynucleotide
coding for an ArgRS or the like and to express a polypeptide coded
for by the polynucleotide.
[0053] For a DNA sequence of ArgRS, refer to GenBank Accession No.
AP.sub.--002496, for example.
[0054] For a DNA sequence of CysRS, refer to GenBank Accession No.
AP.sub.--001173, for example.
[0055] For a DNA sequence of MetRS, refer to GenBank Accession No.
AP.sub.--002712, for example.
[0056] For a DNA sequence of GlnRS, refer to GenBank Accession No.
P00962, for example.
[0057] For a DNA sequence of GluRS, refer to GenBank Accession No.
AP.sub.--001318, for example.
[0058] For a DNA sequence of LysRS, refer to GenBank Accession No.
AP.sub.--004631, for example.
[0059] For a DNA sequence of TyrRS, refer to GenBank Accession No.
AP.sub.--00259, for example.
[0060] For a DNA sequence of TrpRS, refer to GenBank Accession No.
AP.sub.--004406, for example.
[0061] An amino acid serving as a substrate for an aaRS may be
altered with use of a conventional publicly-known method. For such
a method, refer to "Lee, N. et al., Nat Struct Biol, 2000, 7,
28-33" mentioned above, for example. Alternatively, an amino acid
serving as a substrate for an aaRS may be altered by introducing a
mutation into the aaRS according to a technique, described in
International Publication No. 2003/014354 Pamphlet, which involves
the use of PCR. For a method for screening an aaRS mutant obtained
after altering an amino-acid recognition site, refer to "Wang, L.,
Brock, A., Herberich, B., and Schultz, P. G., Expanding the genetic
code of Escherichia coli. Science, 2001 292, 498-500" mentioned
above, for example.
[0062] Further, the altered polypeptide may be a conventional
publicly-known aaRS altered in terms of the amino acid it
recognizes. For example, the altered polypeptide may be an EcIYRS,
a MjIYRS, or the like. Further, the altered polypeptide may be one
of the aaRS mutants disclosed in "Wang, L. et al., Annu Rev Biophys
Biomol Struct, 2006, 35, 225-249". "Wang, L. et al., Annu Rev
Biophys Biomol Struct, 2006, 35, 225-249" enumerates an Escherichia
coli-derived TyrRS mutant specific to p-benzoylphenylalanine, an
Escherichia coli-derived TyrRS mutant specific to
p-azidophenylalanine, an Escherichia coli-derived TyrRS mutant
specific to p-iodophenylalanine, an Escherichia coli-derived TyrRS
mutant specific to p-acetylphenylalanine, a M. jannaschii-derived
TyrRS mutant specific to p-benzoylphenylalanine, a M.
jannaschii-derived TyrRS mutant specific to p-azidophenylalanine, a
M. jannaschii-derived TyrRS mutant specific to p-iodophenylalanine,
a M. jannaschii-derived TyrRS mutant specific to
p-acetylphenylalanine, a M. jannaschii-derived TyrRS mutant
specific to N-acetylgalactosamine-.alpha.-O-threonine, a M.
jannaschii-derived TyrRS mutant specific to
N-acetylglucosamine-.alpha.-O-serine, and the like. Further, the
altered polypeptide of the present invention may be realized by a
M. jannaschii-derived TyrRS mutant specific to
trifluoromethyldiazinylphenylalanine (see Tippmann, E. M. et al.,
Chembiochem, 2007, 8, 2210-2214), a M. jannaschii-derived TyrRS
mutant specific to p-carboxymethylphenylalanine (see Xie, J.,
Supekova, L., Schultz, P. G., ACS Chem. Biol., 2007, 2, 474-478), a
M. jannaschii-derived TyrRS mutant specific to O-allyltyrosine (see
Zhang, Z. et al., Angew. Chem. Int. Ed., 2002, 41, 2840-2842), a M.
jannaschii-derived TyrRS mutant specific to sulfotyrosine (see Liu,
C. C., Schultz, P. G., Nature biotechnology, 2006, 24, 1436-1440),
or the like. Among the examples thus enumerated, EcIYRSs derived
from eubacterial aaRSs are preferred.
[0063] It should be noted that substituting histidine with alanine
at the 70-position, asparagine acid with threonine at the
158-position, and isoleucine with serine at the 159-position of a
Methanococcus jannaschii TyrRS makes it possible to produce a
MjIYRS by altering the substrate amino acid of the TyrRS from
tyrosine to an unnatural amino acid 3-iodotyrosine.
[0064] Further, for example, the altered polypeptide for use in the
polypeptide according to the present invention can be realized by a
polypeptide altered so as to recognize a tyrosine derivative, or in
particular, by a TyrRS mutant obtained by altering a TyrRS so that
3-iodotyrosine is recognized as a tyrosine derivative.
[0065] In this specification, the "tyrosine derivative" means
tyrosine one of whose constituent atoms has a given substituent
introduced thereinto, and the substituent is not limited in
position into which it is introduced. Possible examples of the
tyrosine derivative include tyrosine in which a hydrogen atom bound
to a carbon atom at the 3-position of a phenolic aromatic ring has
been substituted by another atom or a group of atoms, substituted
by a halogen atom, or substituted by an iodine atom (e.g.,
3-iodotyrosine). Further possible examples include tyrosine in
which the 4-position of a phenolic aromatic ring has been
substituted by a group of atoms including an O-methyl group
(O-methyltyrosine), an azido group (azidophenylalanine), a benzoyl
group (parabenzoylphenylalanine), an acetyl group
(4-acetylphenylalanine), and a diazirine group
(trifluoromethyldiazirinylphenylalanine), or by an iodine atom
(4-iodophenylalanine). It should be noted that iodotyrosine is
useful in that it can be used for phase determination in
determining a crystal protein structure.
[0066] Further, an example of a TyrRS mutant obtained by altering a
TyrRS so that the substrate amino acid becomes a tyrosine
derivative is an Escherichia coli-derived TyrRS whose tyrosine at
the 37-position has been substituted by valine, leucine,
isoleucine, or alanine and whose glutamine at the 195-position has
been substituted by alanine, cysteine, serine, or asparagine. The
introduction of the aforementioned substitutions makes it possible
to produce a TyrRS whose substrate amino acid has been altered from
tyrosine to an unnatural amino acid 3-iodotyro sine.
[0067] In one embodiment, it is preferable that the altered
polypeptide be a polypeptide consisting of an amino-acid sequence
represented by SEQ ID NO: 1. The amino-acid sequence represented by
SEQ ID NO: 1 is an amino-acid sequence of a polypeptide obtained by
altering an Escherichia coli-derived TyrRS so that 3-iodotyrosine
is recognized. Further, the altered polypeptide may be a
polypeptide (i) consisting of an amino-acid sequence, represented
by SEQ ID NO: 1 with a deletion, insertion, substitution, or
addition of one or several amino acids and (ii) having activity to
bind 3-iodotyrosine to tRNA.
[0068] [1-2. Editing Polypeptide]
[0069] In this specification, the "editing polypeptide" means a
polypeptide having activity to hydrolyze an aminoacyl adenylate
intermediate and aminoacyl tRNA, each having been produced by an
aaRS's misrecognizing an amino acid different from the correct
substrate amino acid, into an amino acid and an inorganic
phosphoric acid and into an amino acid and tRNA, respectively (such
activity being referred to as "editing reaction activity"). It
should be noted that a domain including the editing polypeptide is
referred to sometimes as "editing reaction domain". aaRSs having
editing polypeptides are an IleRS, a ValRS, a LeuRS, an AlaRS, a
ProRS, a ThrRS, and a PheRS. An editing polypeptide altered so as
to exhibit editing reaction activity to something other than the
aminoacyl tRNA and/or aminoacyl adenylate intermediate the original
aaRS is intended to edit is also encompassed in the scope of
"aaRS-derived editing polypeptide". For example, an IleRS-derived
editing polypeptide, which degrades valyl tRNA, may be altered so
as to hydrolyze binding of an amino acid other than valine (e.g.,
an unnatural amino acid) to tRNA. A person skilled in the art would
be able to appropriately alter an editing polypeptide by
substituting some of the amino acids constituting the editing
polypeptide. However, for convenience of explanation, the term
"aaRS-derived editing polypeptide" used in the description of this
specification means an editing polypeptide that has not been
altered in terms of the aminoacyl tRNA and/or aminoacyl adenylate
intermediate it is intended to edit, if not otherwise
specified.
[0070] There is no particular limit on how to obtain an editing
polypeptide. For example, an editing polypeptide may be obtained as
follows: With use as a template of a polynucleotide coding for an
IleRS, a ValRS, a LeuRS, an AlaRS, a ProRS, a ThrRS, and a PheRS,
the genome DNA of a living organism having these aaRS, or the like,
a polynucleotide coding for the editing polypeptide is obtained by
a nucleic-acid amplification reaction such as PCR with use of a
primer designed based on the base sequence of a conventional
publicly-known editing polypeptide; and with use of the
polynucleotide in a cell-free translation system or a conventional
publicly-known expression system such as a microorganism, a
polypeptide coded for by the polynucleotide is expressed. The
polypeptide may be expressed not only at a site known to be an
active center, but also in an appropriate surrounding domain, among
the editing reaction domain. For example, in the case of the
after-mentioned Pyrococcus horikoshii PheRS, better editing
reaction activity can be obtained by expressing a polypeptide so
that a B3/4 domain is included.
[0071] The PheRS, the IleRS, the ValRS, the LeuRS, the AlaRS, the
ProRS, and the ThrRS, from each of which the editing polypeptide is
obtained, will be detailed below.
[0072] The PheRS is not particularly limited, but can be derived
from eukaryotic organisms or prokaryotic organisms, preferably from
prokaryotic organisms, or in particular, from archaebacteria, more
preferably from the genus Pyrococcus, or most preferably from
Pyrococcus horikoshii. For example, it is possible to use the
beta-subunit of Pyrococcus horikoshii PheRS (refer to GenBank
Accession No. NP.sub.--142611). It should be noted that the
Pyrococcus horikoshii PheRS is disclosed, for example, in "Roy, H.
et al., EMBO J, 2004, 23, 4639-4648", "Kotik-Kogan, O. et al.,
Structure, 2005, 13, 1799-1807", and Sasaki, H., et al., Structural
and mutational studies of the amino acid-editing domain from
archaeal/eukaryal phenylalanyl-tRNA synthetase, Proc Natl Acad Sci
USA, 2006, 103, 14744-14749" and it has been specified that the
B3/4 domain is an editing reaction site. Further, the editing
reaction site of the PheRS has activity to hydrolyze tyrosyl tRNA
and a tyrosyl adenylate intermediate. There are two types of PheRS:
an alpha-subunit and a beta-subunit. Among these, it is the
beta-subunit that includes the editing reaction domain.
[0073] In one embodiment, it is preferable that the editing
polypeptide be a polypeptide consisting of an amino-acid sequence
represented by SEQ ID NO: 2. In another embodiment, it is
preferable that the editing polypeptide be a polypeptide (i)
consisting of an amino-acid sequence, represented by SEQ ID NO: 2
with a deletion, insertion, substitution, or addition of one or
several amino acids and (ii) having editing reaction activity. SEQ
ID NO: 2 represents one of the amino-acid sequences of an editing
polypeptide derived from a Pyrococcus horikoshii-derived PheRS,
i.e., represents the amino-acid sequence of the B3/4 domain. The
polypeptide consisting of these amino-acid sequences may have
another polypeptide bound thereto, as long as the editing reaction
activity is not impaired. For example, the polypeptide consisting
of the amino-acid sequence of the B3/4 domain may have the
after-mentioned B1 and B2 domains bound to the N terminal thereof,
or may have a B5 domain bound to the C terminal thereof.
[0074] It should be noted that the PheRS is an enzyme that
functions by alpha- and beta-heterodimers' combining to form a
further dimer. Among these, the editing reaction domain exists in
the beta-subunit. The beta-subunit consists of B1, B2, B3/4, B5,
B6/7, and B8 domains, and the B3/4 domain is the editing reaction
domain. In a eukaryotic or archaebacterial PheRS, there is a lack
of B2 and B8 domains, i.e., there do not exist B2 and B8 domains.
In some aaRSs, there stably exists a polypeptide including only an
editing reaction domain and hydrolysis activity is retained. The
inventors found that in cases where the editing polypeptide is
obtained from a Pyrococcus horikoshii-derived PheRS, use of a
polypeptide including a B3/4 domain makes it possible to exhibit
extremely stable and satisfactory editing reaction activity.
Therefore, when an editing polypeptide derived from a Pyrococcus
horikoshii PheRS is employed, it is preferable to use a polypeptide
including a B3/4 domain, and it is more preferable to use a
polypeptide consisting of a B3/4 domain.
[0075] It should be noted that also when an editing polypeptide
derived from an Escherichia coli PheRS is employed, it is
preferable to use a polypeptide including a B3/4 domain, and it is
more preferable to use a polypeptide consisting of a B3/4
domain.
[0076] Further, when an editing polypeptide derived from a Thermus
thermophilus is employed, it is preferable to use a polypeptide of
a B3/4 domain or of a B1-B3/4 domain to which B1 and B2 have been
added, because excellent stability is obtained.
[0077] The LeuRS, the IleRS, the ValRS, the AlaRS, the ProRS, and
the ThrRS are not particularly limited, but can be derived
appropriately from eukaryotic organisms or prokaryotic organisms,
preferably from prokaryotic organisms, and will be detailed
below.
[0078] For LeuRS, refer to "Lincecum, T. L. et al., Structural and
Mechanistic Basis of Pre-and Posttransfer Editing by Leucyl-tRNA
Synthetase Molecular Cell, 2003, 11, 951-963", for example, in
which the crystal structure of a T. thermophilus LeuRS is disclosed
and an editing reaction site (domain including Thr247 to Thr252 and
Leu329 to Asp347) is specified. Further, for example, "Fukunaga,
R., and Yokoyama, S., Nat Struct Mol Biol, 2005, 12, 915-922" can
be referred to, in which the crystal structure of a P. horikoshii
LeuRS is disclosed and an editing reaction domain (from the
vicinity of Pro205 to the vicinity of Phe433) is specified.
[0079] For IleRS, refer to "Nureki, O. et al., Science, 1998, 280,
578-582", for example, in which the crystal structure of a T.
thermophilus IleRS is disclosed and an editing reaction site
(domain including Trp232, Phe359, His384, and Tyr386) is
specified.
[0080] For ValRS, refer to "Fukai, S. et al., Cell, 2000, 103,
793-803", for example, in which the crystal structure of a T.
thermophilus ValRS is disclosed and an editing reaction site
(domain including Thr214, Arg216, Thr219, Lys270, Thr272, Asp276,
and Asp279) is specified.
[0081] For AlaRS, refer to "Beebe, K. et al., Distinct domains of
tRNA synthetase recognize the same base pair, Nature, 2008, 451,
90-93", for example, which shows that an E. coli AlaRS polypeptide
including Asp553 to Ala705 has editing reaction activity.
[0082] For ProRS, refer to "Crepin, T. et al., Structures of Two
Bacterial Prolyl-tRNA Synthetases with and without a cis-Editing
Domain, Structure, 2006, 14, 1511-1525", for example, in which the
crystal structure of an Enterococcus faecalis ProRS is disclosed
and an editing reaction domain (Thr237 to Gly390) is specified.
[0083] For ThrRS, refer to "Dock-Bregeon, A.-C. et al., Transfer
RNA-Mediated Editing in Threonyl-tRNA Synthetase: The Class II
Solution to the Double Discrimination Problem, Cell, 2000, 103,
877-884", for example, in which the crystal structure of an E. coli
ThrRS is disclosed and an editing reaction site (domain including
His73, His77, Cys182, and His186) is specified. Further, in FIG. 4
of "Korencic, D. et al., A freestanding proofreading domain is
required for protein synthesis quality control in Archaea, Proc
Natl Acad Scie USA, 2004, 101, 10260-10265", the amino-acid
sequence alignment of an archaebacterial editing reaction domain is
described.
[0084] As for these aaRSs whose editing reaction sites or editing
reaction domains have been specified, polynucleotides coding for
polypeptides containing editing reaction sites or the like are
obtained by a nucleic-acid amplification reaction such as PCR. With
use of the polynucleotides in a conventional publicly-known
expression system, polypeptides coded for by the polynucleotides
are expressed. The polypeptides are checked for editing reaction
activity, and a polypeptide having editing reaction activity is
judged to be an editing polypeptide.
[0085] Further, identical aaRSs share homology with one another
across species in terms of the amino-acid sequence of an editing
reaction site. For this reason, the editing reaction site of an
aaRS of a living organism other than those described above can be
specified by alignment with an aaRS whose editing reaction site has
been specified. Based on this editing reaction site, an editing
polypeptide derived from another living organism can be
appropriately obtained by such a technique as described above.
[0086] [1-3. Positional Relationship Between the Altered
Polypeptide and the Editing Polypeptide]
[0087] As described above, in the polypeptide according to the
present invention, it is preferable that the editing polypeptide
have been either inserted between a Rossman-fold N domain and a
Rossman-fold C domain that exist in the altered polypeptide, or
bound to an N terminal of the altered polypeptide.
[0088] In this specification, the "Rossman-fold domain" means a
domain that universally exists in class I aaRS proteins and forms a
Rossman-fold structure. The "Rossman-fold structure" means a
beta-alpha-beta-alpha-beta structural unit in which beta-alpha-beta
structures each having a concatenation of beta structures and an
alpha helix of a peptide chain are repeated. In a Rossman-fold
domain, there are two Rossman-fold structures arranged. The
Rossman-fold structure on the N terminal is called a "Rossman-fold
N domain", and the Rossmam-fold structure on the C terminal is
called "Rossman-fold C domain". The total six of beta-structures in
the Rossman filed domain are arranged in parallel with one another.
The Rossman-fold structure has activity to bind to a
nucleotide.
[0089] In one embodiment, it is preferable that the editing
polypeptide have been inserted into a CP1 domain that lies between
the Rossman-fold N domain and the Rossman-fold C domain.
[0090] In this specification, the "CP1 (connective peptide 1)
domain" means a domain consisting of an amino acid sandwiched
between N and C domains of a Rossman-fold domain on a primary
sequence of an aaRS of class I.
[0091] Insertion of the editing polypeptide into the CP1 domain
makes it possible to introduce the editing polypeptide while
retaining the activity to bind an amino acid to tRNA.
[0092] In cases where the editing polypeptide has been bound the N
terminal of the altered polypeptide, it is preferable that the N
terminal of the editing polypeptide have been altered to methionine
or an additional peptide whose N terminal is methionine have been
added.
[0093] As described above, if the editing polypeptide is positioned
between the Rossman-fold N domain and the Rossman-fold C domain, or
preferably in the CP1 domain or at the N terminal of the altered
polypeptide, the aminoacylation activity and the editing reaction
activity are effectively exhibited. When inserted into one of the
positions, the editing polypeptide not only can maintain its
three-dimensional structure, but also will not disarray the
three-dimensional structure of the altered polypeptide.
Furthermore, the positional relationship between the editing
polypeptide and the altered polypeptide in the present invention is
appropriate from the point of view that the 3'-end of aminoacylated
tRNA moves rapidly from the altered polypeptide to the editing
polypeptide.
[0094] Further, the polypeptide according to the present invention
may have a linker polypeptide inserted therein, the linker
polypeptide being a polypeptide that connects the editing
polypeptide with the altered polypeptide. The sequence and length
of the linker polypeptide are not limited, and can be set
appropriately by the editing polypeptide and the altered
polypeptide. For example, it is preferable that a linker
polypeptide having 2 to 10 serine or glycine residues be inserted
into each of the N and C terminals of the editing polypeptide.
Further, in cases where the polypeptide according to the present
invention takes such a form that a PheRS-derived editing
polypeptide has been inserted into a TyrRS mutant obtained by
altering a TyrRS so that the amino acid to be recognized is an
unnatural amino acid, it is only necessary that a polypeptide
consisting of an amino-acid sequence represented by SEQ. ID. NO.:
50 be included as a linker at the N terminal of the editing
polypeptide and a polypeptide consisting of an amino-acid sequence
represented by SEQ. ID. NO.: 51 be included as a linker at the C
terminal of the editing polypeptide.
[0095] [1-4. Combination of the Altered Polypeptide and the Editing
Polypeptide]
[0096] As to which of the aaRSs, namely the ArgRS, the CysRS, the
MetRS, the GlnRS, the GluRS, the LysRS, TyrRS, and the TrpRS, is
selected as the altered polypeptide and which of a PheRS-derived
editing polypeptide, an IleRS-derived editing polypeptide, a
ValRS-derived editing polypeptide, a LeuRS-derived editing
polypeptide, an AlaRS-derived editing polypeptide, a ProRS-derived
editing polypeptide, and a ThrRS-derived editing polypeptide is
selected as the editing polypeptide, there is no particular limit
on their combinations. However, preferred combinations will be
described below.
[0097] When the altered polypeptide is an aaRS obtained by altering
the ArgRS, the CysRS, the MetRS, the GlnRS, the GluRS, the LysRS,
the TyrRS, or the TrpRS, it is only necessary to select an editing
polypeptide having activity to hydrolyze an aminoacyl adenylate
intermediate and aminoacyl tRNA, each having been produced by
misrecognition of an amino acid that would not be recognized if the
aaRS were not altered, into an amino acid and an inorganic
phosphoric acid and into an amino acid and tRNA, respectively. This
is because an aaRS altered in terms of the amino acid it recognizes
can be inhibited from misrecognizing the amino acid it recognized
before alteration.
[0098] In fact, it is believed to be the most important and
demanding task in producing an aaRS mutant that specifically
recognizes an unnatural amino acid to inhibit the aaRS from
recognizing the original substrate of the wild-type aaRS (tyrosine
in the case of TyrRS) (Kiga et al., PNAS 99, 9715-9720, 2002;
Summerer et al., PNAS1.03, 9785-9789, 2006).
[0099] For example, in cases where the altered polypeptide is a
TyrRS mutant, it is preferable to use a PheRS-derived editing
polypeptide.
[0100] The PheRS is known to misrecognize tyrosine, which is
similar to phenylalanine, i.e., the original substrate of the
PheRS, to produce tyrosyl tRNAPhe. The editing reaction domain of
the PheRS has activity to hydrolyze an ester bond between tyrosine
in tyrosyl tRNAPhe and tRNA into tyrosine and tRNA. Meanwhile, an
altered polypeptide obtained by altering the TyrRS may misrecognize
tyrosine, which is the original substrate. Introduction of the
editing reaction domain of the PheRS into the TyrRS-derived altered
polypeptide makes it possible to degrade tyrosyl tRNA, which has
been produced by misrecognition of tyrosine by the TyrRS-derived
altered polypeptide, into tyrosine and tRNA. This makes it possible
to prevent tyrosyl tRNA from being produced by misrecognition.
[0101] Further, in cases where the altered polypeptide is a MetRS
mutant, it is preferable to use a LeuRS-derived editing
polypeptide. The MetRS mutant may misrecognize methionine.
Meanwhile, the LeuRS-derived editing polypeptide can hydrolyze
binding of methionine to tRNA.
[0102] That is, in a preferred embodiment of the present invention,
the altered polypeptide is a tyrosyl-tRNA synthetase altered so as
to recognize an unnatural amino acid, and the editing polypeptide
contained an editing reaction active site derived from a
phenylalanyl-tRNA synthetase. Further, in a preferred embodiment of
the present invention, the altered polypeptide is a methionyl-tRNA
synthetase altered so as to recognize an unnatural amino acid, and
the editing polypeptide contains an editing reaction active site
derived from a leucyl-tRNA synthetase.
[0103] [1-5. Other Constituents of the Polypeptide According to the
Present Invention]
[0104] The polypeptide according to the present invention may have
a tag label (tag sequence) added to the N or C terminal thereof,
for example, the tag label being a peptide that facilitates
purification of the polypeptide. Such a sequence can be removed
before the polypeptide is finally prepared. Examples of the tag
sequence include a histidine tag, an HA tag, a Myc tag, and a
Flag.
[0105] In one embodiment, it is preferable that the polypeptide
according to the present invention be a polypeptide consisting of
an amino-acid sequence represented by SEQ. ID. NO: 3.
[0106] Thus far, the constituents of the polypeptide according to
the present invention have been described. In a preferred
embodiment, it is preferable that the polypeptide according to the
present invention be a polypeptide (i) consisting of an amino-acid
sequence, represented by SEQ ID NO: 3 with a deletion, insertion,
substitution, or addition of one or several amino acids, (ii)
having editing reaction activity, and (iii) having activity to bind
an unnatural amino acid to tRNA. SEQ ID NO: 3 is a amino-acid
sequence of Ped-CP1-IYRS described below in Examples, and
represents a polypeptide that exhibits the highest recognition
specificity to 3-iodotyrosine.
[0107] It should be noted that a person skilled in the art can use
a well-known technique to easily mutate one or several amino acids
of the amino-acid sequence of the polypeptide. For example,
according to a publicly-known point mutation introduction method
(mutation induction method), a deletion mutant or an addition
mutant can be produced by designing a primer corresponding to a
given site in a polynucleotide coding for the polypeptide.
[0108] In one aspect, it is preferable that the polynucleotide
according to the present invention code for the polypeptide having
aminoacyl-tRNA synthetase activity. The polynucleotide according to
the present invention may be synthesized from a full-length
polynucleotide by chemical synthesis, or may be synthesized by
ligation of polynucleotides.
[0109] [1-6. Usage of the Polypeptide According to the Present
Invention]
[0110] By introducing the polypeptide according to the present
invention into a cell-free protein translation system, a
eubacterium, or a eukaryotic cell (e.g., a yeast cell, a plant
cell, an insect cell, and a mammalian cell) together with an
unnatural amino acid, a protein containing the unnatural amino acid
can be synthesized in the cell-free protein translation system, the
eubacterium, or the eukaryotic cell.
2. Method According to the Present Invention for Producing a
Polypeptide
[0111] A method according to the present invention for producing a
polypeptide (hereinafter referred to simply as "production method
according to the present invention") is a method for producing a
polypeptide having aminoacyl-tRNA synthetase activity. The method
includes: a preparing step of preparing a polynucleotide in which a
polynucleotide coding for an editing polypeptide containing an
editing reaction active site derived from a PheRS, a LeuRS, an
IleRS, a ValRS, an AlaRS, a ProRS, or a ThrRS has been introduced
into a polynucleotide coding for an altered polypeptide obtained by
altering an ArgRS, a CysRS, a MetRS, a GlnRS, a GluRS, a LysRS, a
TyrRS, or a TrpRS so that an unnatural amino acid is recognized;
and an expressing step of expressing a polypeptide coded for by the
polynucleotide obtained in the preparing step. In the preparing
step, it is only necessary to prepare either a polynucleotide in
which the editing polypeptide has been introduced so as to be
positioned between a Rossman-fold N domain and a Rossman-fold C
domain that exist in the altered polypeptide, or a polynucleotide
in which the editing polypeptide has been introduced so as to be
bound to an N terminal of the altered polypeptide.
[0112] [2-1. Preparing Step]
[0113] The preparing step that is carried out in the present
invention is a step, included in the method for producing a
polypeptide having aminoacyl-tRNA synthetase activity, in which to
prepare a polynucleotide in which a polynucleotide coding for an
editing polypeptide containing an editing reaction active site
derived from a PheRS, a LeuRS, an IleRS, a ValRS, a AlaRS, a ProRS,
or a ThrRS has been introduced into a polynucleotide coding for an
altered polypeptide obtained by altering an ArgRS, a CysRS, a
MetRS, a GlnRS, a GluRS, a LysRS, a TyrRS, or a TrpRS so that an
unnatural amino acid is recognized, in which step (i) a
polynucleotide in which the polynucleotide coding for the editing
polypeptide has been introduced so as to be positioned between a
Rossman-fold N domain and a Rossman-fold C domain in the
polynucleotide coding for the altered polypeptide that recognizes
the unnatural amino acid or (ii) a polynucleotide in which the
editing polypeptide has been introduced so as to be bound to an N
terminal of the altered polypeptide is prepared.
[0114] A person skilled in the art can use a well-known technique
so that the polynucleotide coding for the editing polypeptide is
introduced into a position corresponding to the space between a
Rossman-fold N and C domains of the polynucleotide coding for the
altered polypeptide or bound to a position corresponding to the N
terminal of the altered polypeptide. For example, the
polynucleotide coding for the editing polypeptide and the
polynucleotide coding for the altered polypeptide can be bound with
a ligase after being obtained by a nucleic-acid amplification
reaction such as PCR.
[0115] There is no particular limit on a template for use in the
nucleic-acid amplification reaction. However, it is possible to use
a plasmid containing genome DNA, cDNA, and a clone of the
polynucleotide. Further, it is possible to bind fragments cut out
from the plasmid by restriction enzyme digestion. Further, as will
be described below in Examples, it is possible to prepare a
template by overlap PCR. Further, it is possible to chemically
synthesize a full-length polynucleotide of the polynucleotide
coding for the editing polypeptide and the polynucleotide coding
for the altered polypeptide.
[0116] [2-2. Expressing Step]
[0117] Use of the polynucleotide obtained in the preparing step
makes it possible to transform eubacteria such as Escherichia coli
or eukaryotic cells (e.g., yeast cells, plant cells, insect cells,
and mammalian cells) and express, in the transformed cells, a
polypeptide coded for by the polynucleotide obtained in the
preparing step. Further, it is possible to perform transcription
and protein synthesis in a conventionally publicly-known rabbit
reticulocyte, insect, or wheat cell-free system.
[0118] The polynucleotide obtained in the preparing step can be
incorporated into an expression vector. There is no particular
limit on the specific type of vector, and it is possible to
appropriately select a vector capable of expression in a host cell
for use in expression. That is, it is only necessary to select,
according to the type of host cell, an appropriate promoter
sequence for surely expressing a polypeptide coded for by the
polynucleotide according to the present invention and use, as an
expression vector, a vector obtained by incorporating the promoter
sequence and the polynucleotide according to the present invention
into various plasmids. It should be noted that the vector is not
limited to a case where the objective protein is constitutively
synthesized, but may be induced by addition of IPTG to be
synthesized. Further, the vector may include a sequence that adds a
tag sequence such as a histidine tag, an HA tag, a Myc tag, or a
Flag to the N or C terminal of the protein to be synthesized.
[0119] After a host transformed with use of the expression vector
is cultured, the objective protein can be collected from the
culture or the like and purified according to a conventional
technique (e.g., filtration, centrifugation, cell breakage, gel
filtration chromatography, ion-exchange chromatography). Further,
in cases where the tag has been added to the protein to be
synthesized, the objective protein can be easily collected.
[0120] It is preferable that the expression vector include at least
one selective marker. As for eukaryotic cell culture, an example of
such a marker is a dihydrofolate reductase or a drug-resistant gene
such as neomycin, zeocin, geneticin, blasticidin S, or hygromycin
B. As for culture of Escherichia coli and other bacteria, an
example of such a marker is a drug-resistant gene such as
kanamycin, zeocin, actinomycin D, cefotaxime, streptomycin
carbenicillin, puromycin, tetracycline, or ampicillin.
[0121] Use of the selective marker makes it possible to confirm
whether or not the polynucleotide according to the present
invention has been introduced into a host cell, and to further
confirm whether or not the polynucleotide according to the present
invention has been surely expressed in the host cell.
[0122] The host cell is not particularly limited, and can be
suitably realized by various conventional publicly-known cells.
[0123] The method for introducing a polynucleotide according to the
present invention or an expression vector including a
polynucleotide according to the present invention into a host cell,
i.e., the transformation method is not particularly limited, and
can be suitably realized by a conventional publicly-known method
such as electroporation or a calcium-phosphate method.
[0124] The embodiments of the present invention will be further
detailed below with reference to examples. The present invention is
not limited to the following examples, and details of the present
invention can take various aspects. Furthermore, the present
invention is not limited to the description of the embodiments
above, but may be altered by a skilled person within the scope of
the claims. An embodiment based on a proper combination of
technical means disclosed in different embodiments is encompassed
in the technical scope of the present invention. Further, all the
documents cited in this specification can be cited as
references.
Example 1
Construction of Editing Reaction Peptide Expression Plasmids
[0125] As mentioned above, the beta-subunit of PheRS consists of
B1, B2, B3/4, B5, B6/7, and B8 domains, and the B3/4 domain is an
editing reaction domain.
[0126] In the beta-subunit of PheRS, the B6/7 and B8 domains is
placed separately from the B3/4 domain because of the
three-dimensional structure. Further, it is believed that there is
no fixed structure formed between the B5 domain and the B6/7
domain.
[0127] In view of this, the present example uses, as an editing
polypeptide, a polypeptide fragment (hereinafter referred to as
"editing reaction peptide") including the B3/4 domain, and as such,
does not include the B6/7 domain and the B8 domain.
[0128] With use of the genome DNA of E. coli, the genome DNA of T.
thermophilus, and the genome DNA of P. horikoshii as templates, a
DNA fragment coding for the BH to B5 domains (B1-B5) of the
beta-subunit of PheRS of each living organism, a DNA fragment
coding for the BH to B3/4 domains (B1-B3/4) of the beta-subunit, a
DNA fragment coding for the B3/4 to B5 domains (B3/4-B5) of the
beta-subunit, and a DNA fragment coding for only the B3/4 domain of
the beta-subunit were amplified by PCR.
[0129] Specifically, the 1st to 475th amino-acid residues of the
amino-acid sequence of the beta-subunit of PheRS of E. coli, the
1st to 403rd amino-acid residues of the amino-acid sequence, the
188th to 475th amino-acid residues of the amino-acid sequence, and
the 188th to 403rd amino-acid residues of the amino-acid sequence
were used as B1-B5, B1-B3/4, B3/4-B5, and B3/4, respectively. The
amino-acid sequence is represented by SEQ. ID. NO: 52.
[0130] As for PheRS of T. thermophilus, the 1st to 473rd amino-acid
residues of the amino-acid sequence of the beta-subunit of PheRS of
T. thermophilus, the 1st to 401st amino-acid residues of the
amino-acid sequence, the 190th to 473rd amino-acid residues of the
amino-acid sequence, and the 190th to 401st amino-acid residues of
the amino-acid sequence were used as B1-B5, B1-B3/4, B3/4-B5, and
B3/4, respectively. The amino-acid sequence is represented by SEQ.
ID. NO: 53.
[0131] As for PheRS of P. horikoshii, the 1st to 353rd amino-acid
residues of the amino-acid sequence of the beta-subunit of PheRS of
P. horikoshii, the 1st to 280th amino-acid residues of the
amino-acid sequence, the 83rd to 353rd amino-acid residues of the
amino-acid sequence, and the 83rd to 280th amino-acid residues of
the amino-acid sequence were used as B1-B5, B1-B3/4, B3/4-B5, and
B3/4, respectively. The amino-acid sequence is represented by SEQ.
ID. NO: 54.
[0132] The DNA fragments coding for their respective domains of E.
coli were amplified as follows. Specifically, the DNA fragment
coding for B1-B5 was amplified by PCR with use of primers Ec-B1-F
(SEQ. ID. NO: 55) and Ec-B5-R (SEQ. ID. NO: 56). The DNA fragment
coding for B1-B3/4 was amplified by PCR with use of primers Ec-B1-F
and Ec-B3/4-R (SEQ. ID. NO: 57). The DNA fragment coding for
B3/4-B5 was amplified by PCR with use of primers Ec-B3/4-F (SEQ.
ID. NO: 58) and Ec-B5-R. The DNA fragment coding for B3/4 was
amplified by PCR with use of primers Ec-B3/4-F and Ec-B3/4-R.
[0133] The DNA fragments coding for their respective domains of T.
thermophilus were amplified as follows. Specifically, the DNA
fragment coding for B1-B5 was amplified by PCR with use of primers
Tt-B1-F (SEQ. ID. NO: 59) and Tt-B5-R (SEQ. ID. NO: 60). The DNA
fragment coding for B1-B3/4 was amplified by PCR with use of
primers Tt-B1-F and Tt-B3/4-R (SEQ. ID. NO: 61). The DNA fragment
coding for B3/4-B5 was amplified by PCR with use of primers
Tt-B3/4-F (SEQ. ID. NO: 62) and Tt-B5-R. The DNA fragment coding
for B3/4 was by PCR amplified with use of primers Tt-B3/4-F and
Tt-B3/4-R.
[0134] The DNA fragments coding for their respective domains of P.
horikoshii were amplified as follows. Specifically, the DNA
fragment coding for B1-B5 was amplified by PCR with use of primers
Ph-B1-F (SEQ. ID. NO: 63) and Ph-B5-R (SEQ. ID. NO: 64). The DNA
fragment coding for B1-B3/4 was amplified by PCR with use of
primers Ph-B1-F and Ph-B3/4-R (SEQ. ID. NO: 65). The DNA fragment
coding for B3/4-B5 was amplified by PCR with use of primers
Ph-B3/4-F (SEQ. ID. NO: 66) and Ph-B5-R. The DNA fragment coding
for B3/4 was amplified by PCR with use of primers Ph-B3/4-F and
Ph-B3/4-R.
[0135] In each case, PCR was carried out under the following
thermocycling conditions: 98.degree. C. for 1 minute; 98.degree. C.
for 10 seconds, 54.degree. C. for 30 seconds, and 72.degree. C. for
1 minute (25 cycles). The DNA polymerase used was Phusion
High-Fidelity DNA Polymerase (NEB, Inc.).
[0136] Each of the DNA fragments thus amplified was introduced
between the NdeI and XhoI sites of a vector pET-26b (Novagen, Inc.)
so that His-tag was added to the C terminal of the polypeptide to
be expressed. Thus produced was an editing reaction peptide
expression plasmid. The editing reaction peptide expression plasmid
was cloned.
Example 2
Expression and Purification of Editing Reaction Peptides
[0137] With use of each of the expression plasmids thus cloned,
Escherichia coli BL21 Star (DE3) (Invitrogen Corporation) was
transformed, and then cultured at 37.degree. C. in an LB medium
containing 50 .mu.g/ml of kanamycin. At the point of time where the
O.D. 600 of the culture fluid took on a value of 0.4 to 0.6, IPTG
was added so that the final concentration was 1 mM. After the
addition of IPTG, the culture temperature was lowered to 20.degree.
C. In this manner, the expression of each editing reaction peptide
was induced. Twenty hours after the start of induction, the
bacteria were harvested.
[0138] Next, the editing reaction peptide was extracted from the
bacteria thus harvested, and purified. A lytic buffer solution was
prepared by adding a grain of a protease inhibitor Complete (Roche)
to 200 ml of a buffer solution A (20 mM Tris-Cl (ph 8.0), 300 mM
NaCl, 30 mM imidazole, 5 mM 2-mercaptoethenol). The harvested
bacteria were suspended in the lytic buffer solution, and then were
subjected to sonication. An insoluble fraction was precipitated by
centrifugation. Each editing reaction peptide, contained in a
supernatant, was adsorbed to a resin Ni Sepharose 6 Fast Flow (GE
Healthcare, Inc.) equilibrated with use of the lytic buffer
solution. After the resin had been washed with the lytic buffer
solution, the editing reaction peptide was eluted from the resin
with use of a buffer solution B obtained by increasing the
imidazole concentration of the buffer solution A to 500 mM.
[0139] The eluate was diluted with use of 20 mM Tris-Cl (ph 8.0) so
that the concentrations of Tris-Cl, NaCl, and imidazole in the
eluate became 20 mM Tris-Cl (ph 8.0), 75 mM NaCl, and 125 mM
imidazole. As for the eluate thus diluted, a protein was
concentrated with use of Amicon-Ultra 4 (Millipore Corporation)
until the volume became approximately 100 .mu.l. The concentrated
protein was put with glycerol so that the final concentration
became 50%, mixed well, and preserved at -20.degree. C.
[0140] The twelve types of editing reaction peptide thus obtained
varied slightly in expression level, depending on the types of
living organism, but were expressed so that soluble fractions were
generally obtained. Further, none of them aggregated when
concentrated.
Example 3
Hydrolysis Activity of the Editing Reaction Peptides
[0141] Next, the hydrolysis activity of each of the editing
reaction peptides was measured. The measurement of the hydrolysis
activity of each of the editing reaction peptides was performed by
measuring the extent to which tyrosylation of tRNA.sup.Tyr by
EcIYRS was inhibited, instead of directly measuring hydrolysis in
tyrosyl tRNA.sup.Tyr. EcIYRS was obtained in the following manner.
That is, a pET-26b-derived plasmid (donated from Dr. Kobayashi of
RIKEN) cloned so that His-tag sticks to the C terminal of EcIYRS
was used to transform Escherichia coli BL21 Star (DE3) (Invitrogen
Corporation) The subsequent operations were performed in the same
manner as in the aforementioned expression and purification of
editing reaction peptides.
[0142] It should be noted that the base sequence of EcIYRS is
represented by SEQ. ID. NO: 4. It should also be noted that the
amino-acid sequence of EcIYRS is an amino-acid sequence represented
by the aforementioned SEQ. ID. NO: 1.
[0143] A reaction solution was prepared in an amount of 20 .mu.l by
adding 200 mM tyrosine, 1 .mu.M EcIYRS, and 2.5 .mu.M editing
reaction peptide to an aminoacylation buffer solution (100 mM
Tris-Cl (pH 7.5), 15 mM MgCl.sub.2, 5 .mu.M tRNA.sup.Tyr, 4 mM
ATP). The reaction solution was incubated at 37.degree. C. for 25
minutes. The reaction was terminated by adding, to the reaction
solution, an equal volume of a solution containing 300 mM sodium
acetate (pH 5.0), 8 M urea, 0.05% bromophenol blue, and 0.05%
xylene cyanol. Next, the reaction solution was subjected to
electrophoresis (urea-denatured acidic PAGE) with use of 8 M urea
denatured 7% (w/v) polyacrylamide gel (acrylamide:
bisacrylamide=29:1) equilibrated with 0.1 M sodium acetate (pH
5.0). The electrophoretic buffer solution used was 0.1 M sodium
acetate (pH 5.0). The electrophoresis was performed for 10 to 14
hours under the following conditions: a temperature of 4.degree.
C.; and a current of 24 to 30 mA. After the electrophoresis, tRNA
was detected by staining the gel with toluidine blue.
[0144] FIG. 1 shows the results of electrophoresis. (a) to (c) of
FIG. 1 show that with no addition of editing reaction peptides,
EcIYRS tyrosylated tRNA.sup.Tyr and the bands of tRNA shifted
almost completely (Lanes 2). From this, it can be judged that the
decreases in shift of bands at the time of addition of the editing
reaction peptides are attributed to the hydrolyses caused by the
editing reaction peptides.
[0145] As for the case of addition of the E. coli-derived editing
peptides, remarkable decreases in shift of bands were observed in
the case of addition of the B1-B3/4, B3/4-B5, and B3/4 editing
reaction peptides (Lanes 4, 5, and 6 of FIG. 1(a)). As for the case
of addition of the T. thermophilus editing reaction peptides, a
decrease in shift of a band was observed in the case of addition of
the B1-B3/4 editing reaction peptide (Lane 4 of FIG. 1(b)). As for
the case of addition of the P. horikoshii editing reaction
peptides, decreases in shift of bands were observed in the case of
addition of the B1-B5 and B3/4 editing reaction peptides (Lanes 3
and 6 of FIG. 1(c)).
[0146] These results show that a polypeptide fragment including a
B3/4 domain retains hydrolysis activity even if it is not a
full-length protein. As for the E. coli- and P. horikoshii-derived
editing reaction peptides, even the shortest editing reaction
peptides retain hydrolysis activity.
[0147] Meanwhile, in the case of T. thermophilus, extremely
satisfactory hydrolysis activity was exhibited in the case of use
of the B1-B3/4, to which the B1 and B2 domains had been added, in
comparison with the B3/4.
Example 4
Construction of N-Terminal Fusion Protein Expression Plasmids
[0148] Plasmids for expressing fusion proteins each having an
editing reaction peptide introduced at the N terminal of EcIYRS
were constructed.
[0149] Among the E. coli-, P. horikoshii-, and T.
thermophilus-derived editing reaction peptides, the smallest
editing reaction peptide was fused with the N terminal of EcIYRS.
That is, as for each of the E. coli and P. horikoshii editing
reaction peptides, the editing reaction domain B3/4 was used. As
for the T. thermophilus editing reaction peptide, the editing
reaction domain B1-B3/4 was used.
[0150] It should be noted that the amino-acid sequence of the E.
coli-derived B3/4 domain is represented by SEQ. ID. NO: 5 and the
base sequence is represented by SEQ. ID. NO: 6. The amino-acid
sequence of the P. horikoshii-derived B3/4 domain is represented by
SEQ. ID. NO: 2 and the base sequence is represented by SEQ. ID. NO:
7. The amino-acid sequence of the T. thermophilus-derived B1-B3/4
domain is represented by SEQ. ID. NO: 8 and the base sequence is
represented by SEQ. ID. NO: 9.
[0151] It should be noted that the mutants are named "Eed-N-IYRS"
(E. coli), "Ted-N-IYRS" (T. thermophilus), and "Ped-N-IYRS" (P.
horikoshii) after the original species and sites of fusion of the
editing reaction domains. FIG. 2 schematically shows the
constituents of each of the fusion proteins.
[0152] Further, from each of the fusion proteins, a mutant was
produced by inactivating the editing reaction activity of the
fusion protein (Eed.sup.mu-N-IYRS, Ted.sup.mu-N-IYRS, and
Ped.sup.mu-N-IYRS). In each of Eed.sup.mu-N-IYRS and
Tedd.sup.mu-N-IYRS, Ala356 in the original PheRS beta-subunit had
been substituted with Trp. In Ped.sup.mu-N-IYRS, Ala141 in the
original PheRS beta-subunit had been substituted with Trp. These
two types of amino-acid residue are structurally at substantially
the same location. The mutation causes Trp to be embedded in a
substrate-binding pocket, with the result that the editing reaction
activity is lost.
[0153] The mutation that inactivates editing reaction was
introduced site-specifically by amplifying the whole plasmid by
PCR. The Eed.sup.mu-N-IYRS expression plasmid was produced with use
of the Eed-N-IYRS expression plasmid as a template by amplifying
the whole plasmid by PCR with use of primers Ec-Mu-F (SEQ. ID. NO:
67) and Ec-Mu-R (SEQ. ID. NO: 68). Further, the Ted.sup.mu-N-IYRS
expression plasmid was produced with use of the Ted-N-IYRS
expression plasmid as a template by amplifying the whole plasmid by
PCR with use of primers Tt-Mu-F (SEQ. ID. NO: 69) and Tt-Mu-R (SEQ.
ID. NO: 70). The Ped.sup.mu-N-IYRS expression plasmid was produced
with use of the Ped-N-IYRS expression plasmid as a template by
amplifying the whole plasmid by PCR with use of primers Ph-Mu-F
(SEQ. ID. NO: 71) and Ph-Mu-R (SEQ. ID. NO: 72). In each case, PCR
was carried out under the following thermocycling conditions:
98.degree. C. for 1 minute; 98.degree. C. for 10 seconds,
54.degree. C. for 30 seconds, and 72.degree. C. for 2 minutes and
30 seconds (16 cycles). The DNA polymerase used was Phusion
High-Fidelity DNA Polymerase.
[0154] With use of the genome DNA of E. coli as a template, DNA
coding for the B3/4 domain of E. coli was amplified by PCR with use
of primers EcN1 (SEQ. ID. NO: 15) and EcN2 (SEQ. ID. NO: 16). PCR
was carried out under the following thermocycling conditions:
98.degree. C. for 1 minute; 98.degree. C. for 10 seconds,
54.degree. C. for 30 seconds, and 72.degree. C. for 1 minute (25
cycles). After the last cycle, the reacted solution was preserved
at 72.degree. C. for 5 minutes.
[0155] With use as a template of a plasmid A (donated from Dr.
Kobayashi of RIKEN) containing DNA coding for EcIYRS, the DNA
coding for EcIYRS was amplified by PCR with use of primers EcN3
(SEQ. ID. NO: 17) and EcN4 (SEQ. ID. NO: 18). PCR was carried out
under the same thermocycling conditions as the DNA coding for the
B3/4 domain of E. coli had been amplified.
[0156] Next, a DNA fragment coding for a fusion protein in which
the B3/4 domain of the E. coli PheRS beta-subunit had been added to
the N terminal of the EcIYRS protein was amplified by overlap PCR
with use of the PCR-amplified DNA coding for the B3/4 domain of E.
coli, the PCR-amplified DNA coding for EcIYRS, and primers EcN5
(SEQ. ID. NO: 19) and EcN6 (SEQ. ID. NO: 20). First, a reaction
solution containing neither of the primers EcN5 and EcN6 was
prepared. With use of this reaction solution, PCR was carried out
under the following thermocycling conditions: 98.degree. C. for 1
minute; 98.degree. C. for 10 seconds, 57.degree. C. for 30 seconds,
and 72.degree. C. for 1 minute (8 cycles). After the 8 cycles, the
primers EcN5 and EcN6 were added to the reaction solution. With use
of the reaction solution to which the primers had been added, PCR
was carried out under the following thermocycling conditions:
98.degree. C. for 1 minute; 98.degree. C. for 10 seconds,
57.degree. C. for 30 seconds, and 72.degree. C. for 1 minute 45
seconds (26 cycles). After the last cycle, the reacted solution was
preserved at 72.degree. C. for 5 minutes. The amplified DNA was
inserted between the NdeI and XhoI sites of an expression vector
pET-26b (Novagen, Inc.) so that a His tag was added. Thus produced
was an Eed-N-IYRS expression plasmid. The base sequence of
Eed-N-IYRS is represented by SEQ. ID. NO: 10.
[0157] With use of the genome DNA of T. thermophilus, DNA coding
for the B1-B3/4 domain of T. thermophilus was amplified by PCR with
use of primers TtN1 (SEQ. ID. NO: 21) and TtN2 (SEQ. ID. NO: 22).
PCR was carried out under the following thermocycling conditions:
98.degree. C. for 1 minute; 98.degree. C. for 10 seconds,
72.2.degree. C. for 30 seconds, and 72.degree. C. for 1 minute (25
cycles). After the last cycle, the reacted solution was preserved
at 72.degree. C. for 5 minutes.
[0158] With use of the plasmid A as a template, DNA coding for
EcIYRS was amplified by PCR with use of primers TtN3 (SEQ. ID. NO:
23) and TtN4 (SEQ. ID. NO: 24).
[0159] Next, a DNA fragment coding for a fusion protein in which
the B3/4 domain of the T. thermophilus had been added to the N
terminal of the EcIYRS protein was amplified by overlap PCR with
use of the PCR-amplified DNA coding for the B1-B3/4 domain of T.
thermophilus, the PCR-amplified DNA coding for EcIYRS, and primers
TtN5 (SEQ. ID. NO: 25) and TtN6 (SEQ. ID. NO: 26). First, a
reaction solution containing neither of the primers TtN5 and TtN6
was prepared. With use of this reaction solution, PCR was carried
out. The reaction was paused. The primers TtN5 and TtN6 were added.
The reaction was resumed. The specific conditions for overlap PCR
were the same as those under which the DNA coding for Eed-N-IYRS
had been prepared. The amplified DNA was inserted between the NdeI
and XhoI sites of a vector pET-26b (Novagen, Inc.) so that a His
tag was added. Thus produced was a Ted-N-IYRS expression plasmid.
The base sequence of Ted-N-IYRS is represented by SEQ. ID. NO:
11.
[0160] With use of the genome DNA of P. horikoshii as a template,
DNA coding for the B3/4 domain of P. horikoshii was amplified by
PCR with use of primers PhN1 (SEQ. ID. NO: 27) and PhN2 (SEQ. ID.
NO: 28). PCR was carried out under the following thermocycling
conditions: 98.degree. C. for 1 minute; 98.degree. C. for 10
seconds, 57.degree. C. for 30 seconds, and 72.degree. C. for 1
minute (25 cycles). After the last cycle, the reacted solution was
preserved at 72.degree. C. for 5 minutes.
[0161] With use of the plasmid A as a template, DNA coding for
EcIYRS was amplified by PCR with use of primers PhN3 (SEQ. ID. NO:
29) and PhN4 (SEQ. ID. NO: 30).
[0162] Next, a DNA fragment coding for a fusion protein in which
the B3/4 domain of the P. horikoshii had been added to the N
terminal of the EcIYRS protein was amplified by overlap PCR with
use of the PCR-amplified DNA coding for the B3/4 domain of P.
horikoshii, the PCR-amplified DNA coding for EcIYRS, and primers
PhN5 (SEQ. ID. NO: 31) and PhN6 (SEQ. ID. NO: 32). First, a
reaction solution containing neither of the primers PhN5 and PhN6
was prepared. With use of this reaction solution, PCR was carried
out under the following thermocycling conditions: 98.degree. C. for
1 minute; 98.degree. C. for 10 seconds, 57.degree. C. for 30
seconds, and 72.degree. C. for 1 minute (8 cycles). After the 8
cycles, the primers PhN5 and PhN6 were added to the reaction
solution. With use of the reaction solution to which the primers
had been added, PCR was carried out under the following
thermocycling conditions: 98.degree. C. for 1 minute; 98.degree. C.
for 10 seconds, 57.degree. C. for 30 seconds, and 72.degree. C. for
1 minute (25 cycles). After the last cycle, the reacted solution
was preserved at 72.degree. C. for 5 minutes. The amplified DNA was
inserted between the NdeI and XhoI sites of an expression vector
pET-26b (Novagen, Inc.) so that a His tag was added. Thus produced
was a Ped-N-IYRS expression plasmid. The base sequence of
Ped-N-IYRS is represented by SEQ. ID. NO: 12.
[0163] In the PCR of the present example, including the
after-mentioned PCR, the polymerase used was Phusion High-Fidelity
DNA Polymerase (NEB, Inc.).
[0164] The expression and purification of each fusion protein were
performed in the same manner as in Example 2, except that the
culture temperature conditions after the induction of expression
were changed to 24.degree. C. Further, the expression was confirmed
by SDS-PAGE (not shown).
Example 5
Determination of the Aminoacylation Activity of the N-Terminal
Fusion Proteins
[0165] Next, the aminoacylation activity (tyrosylation activity) of
each of the fusion proteins was determined. An aminoacylation
reaction solution was prepared by adding 30 .mu.M
[.sup.14C]-L-tyrosine (GE Healthcare) and 1 .mu.M aaRS to an
aminoacylation buffer solution. By incubating the reaction solution
at 37.degree. C., aminoacylation was performed, with the result
that [.sup.14C]-L-tyrosyl tRNA.sup.Tyr was produced.
[.sup.14C]-L-tyrosyl tRNA.sup.Tyr was precipitated on a piece of
filter paper with 10% trichloroacetic acid (TCA). After the piece
of filter paper had been washed with 5% TCA and 100% ethanol, the
radioactivity of the piece of filter paper was measured by a liquid
scintillation counter. Since the piece of filter paper adsorbs only
a high-molecular substance, unreacted [.sup.14C]-tyrosine is washed
away, so that only tyrosylated tRNA, i.e., [.sup.14C]-tyrosyl
tRNA.sup.Tyr can be measured. Such radioactivity was used to
determine the extent to which each fusion protein recognized
tyrosine.
[0166] FIG. 3 shows the results of determination of recognition of
tyrosine. As shown in FIG. 3, the mutants, in each of which an
altered editing reaction domain obtained by inactivating the
editing reaction activity of an editing reaction domain had been
added to the N terminal, maintained the same level of tyrosylation
activity as EcIYRS, regardless of the species of editing reaction
domain with which the mutants had been fused. This shows that the
tyrosylation activity of EcIYRS is hardly lowered due to the fusion
of an exogenous sequence with the N terminal. Therefore, it can be
said that the decreases in tyrosylation activity at the time of
fusion of the wild-type editing reaction domains are attributed to
the hydrolyses caused by the editing reactions.
[0167] A certain level of decrease in tyrosylation was seen
regardless of the species of editing reaction domain fused. In each
of the cases where the editing reaction domains of bacteria E. coli
and T. thermophilus were added, it was confirmed that the amount of
[.sup.14C]-tyrosyl tRNA.sup.Tyr detected was half as large as in
the case where EcIYRS was used. That is, it was confirmed that the
activity was half as high as that of EcIYRS. Further, in the case
where the editing reaction domains of archaebacteria P. horikoshii
was added, it was confirmed that [.sup.14C]-tyrosyl tRNA.sup.Tyr
was hardly detected and the tyrosylation of tRNA.sup.Tyr was
inhibited.
[0168] Next, each of the fusion proteins was assayed for substrate
specificity. A reaction solution was prepared by adding 200 .mu.M
tyrosine or 3-iodotyrosine and 1 .mu.M fusion protein to an
aminoacylation buffer solution. The reaction solution was incubated
at 24.degree. C. for 30 minutes. The reaction was terminated by
adding, to the reaction solution, an equal volume of a solution
containing 300 mM sodium acetate (pH 5.0), 8 M urea, 0.05%
bromophenol blue, and 0.05% xylene cyanol. The reaction solution
was subjected to urea-denatured acidic PAGE in the same manner as
in the aforementioned determination of the hydrolysis activity of
the editing reaction peptides, whereby a shift in band of tRNA was
observed. The assay makes it possible to confirm whether or not
3-iodotyrosine is recognized.
[0169] FIG. 4 shows the results of assaying the fusion proteins for
their substrate specificity. As shown in FIG. 4, Eed-N-IYRS,
Ted-N-IYRS, and Ped-N-IYRS showed no band shifts in cases where
tyrosine was used (Lanes 4, 6, and 8), but showed band shifts in
cases where iodotyrosine was used (Lanes 5, 7, and 9). In contrast,
EcIYRS, which does not contain an editing reaction domain, showed a
band shift also in cases where tyrosine was used (Lane 2). This
shows that an editing reaction domain does not degrade
3-iodotyrosyl tRNA.sup.Tyr and only tyrosyl tRNA is recognized and
degraded by using an editing reaction domain.
Example 6
Search for a Place to Insert an Editing Reaction Domain
[0170] The aaRSs classified into class I share a common basic
structure, i.e., a Rossman-fold domain, and each of the aaRSs
further has an additional domain inserted at the N terminal of the
Rossman-fold domain, at the C terminal of the Rossman-fold domain,
or into the Rossman-fold domain. Locations where these insertion
sequences exist are considered to be places where another sequence
can be inserted without disarraying the Rossman-fold structure.
[0171] The amino-acid sequences of the 2,467 types of class I aaRS
registered in Swiss-prot were aligned. The software used for
alignment was MAFFT (Katoh, K., Misawa, K., Kuma, K., and Miyata
T., MAFFT: a novel method for rapid multiple sequence alignment
based on fast Fourier transform. Nucleic Acids Res, 2002, 30,
3059-3066; Katoh, K., Kuma, K., Toh, H., and Miyata, T., MAFFT
version 5: improvement in accuracy of multiple sequence alignment.
Nucleic Acids Res, 2005, 33, 511-518).
[0172] As a result of alignment of the primary sequences of the
class I aaRSs, each of the class I aaRSs showed some characteristic
insertion sequences. Among those insertion sequences, the most
remarkable insertion sequences were the CP1 domains of ValRS,
IleRS, and LeuRS. In ValRS, IleRS, and LeuRS, the CP1 domains were
editing reaction domains.
[0173] A CP1 domain is an insertion sequence that every class I
aaRS has inside of the Rossman fold. Each of the class I aaRSs has
a CP1 domain inserted at the same site in the Rossman fold as the
other. CP1 domains vary in length and function from aaRS to aaRS.
The three CP1 domains of ValRS, IleRS, and LeuRS are the longest,
i.e., as long as approximately 200 amino-acid residues, and serve
as editing reaction domains. Meanwhile, the CP1 domain of TyrRS is
as short as approximately 70 amino-acid residues. The CP1 domain of
TyrRS involves in tRNA recognition, dimerization, and substrate
recognition. In this alignment, the editing reaction domains of
ValRS, IleRS, and LeuRS were inserted between the 166th and 167th
resides of a loop domain (163rd to 169th amino-acid residues) that
exists in the CP1 domain of TyrRS. This loop is not in contact with
any other domain in the CP1 domain, and as such, has no particular
function. Therefore, it was supposed that the structure of EcIYRS
would not be disarrayed even if an editing reaction domain was
inserted. In view of this, it was decided that the editing reaction
domain of PheRS was inserted into the loop domain.
[0174] The editing reaction domain was realized by a P.
horikoshii-derived editing reaction domain. The resultant EcIYRS
mutant is named "Ped-CP1-IYRS" after the place where the editing
reaction domain has been inserted. That is, the editing reaction
domain has been inserted in the CP1 domain of Ped-CP1-IYRS.
[0175] For comparison, the following discusses an EcIYRS mutant
obtained by inserting the editing reaction domain into the AC
binding domain. The EcIYRS mutant is hereinafter referred to as
"Ped-AC-IYRS".
[0176] FIG. 2 schematically shows the constituents of each of these
fusion proteins. For ease of comparison, FIG. 2 also shows EcIYRS
and the fusion proteins produced in Example 4.
Example 7
Construction of a Ped-CP1-IYRS Expression Plasmid
[0177] With use of the genome DNA of P. horikoshii as a template,
DNA coding for the B3/4 domain of P. horikoshii was amplified by
PCR with use of primers PhC1 (SEQ. ID. NO: 33) and PhC2 (SEQ. ID.
NO: 34). PCR was carried out under the following thermocycling
conditions: 98.degree. C. for 1 minute; 98.degree. C. for 10
seconds, 55.degree. C. for 30 seconds, and 72.degree. C. for 1
minute (25 cycles). After the last cycle, the reacted solution was
preserved at 72.degree. C. for 2 minutes.
[0178] With use of the plasmid A as a template, DNA coding for the
first to 166th amino-acid residues of EcIYRS and DNA coding for the
167th to 424th amino-acid residues of EcIYRS were amplified by PCR
with use of primers PhC3 (SEQ. ID. NO: 35) and PhC4 (SEQ. ID. NO:
36) and by PCR with use of primers PhC5 (SEQ. ID. NO: 37) and PhC6
(SEQ. ID. NO: 38).
[0179] Next, a DNA fragment coding for a fusion protein in which
the B3/4 domain of P. horikoshii had been inserted into the CP1
domain of EcIYRS was amplified by PCR with use of the PCR-amplified
DNA coding for the B3/4 domain of P. horikoshii, the PCR-amplified
DNA coding for the N (1-166) and C (167-424) terminals of EcIYRS,
and primers PhC7 (SEQ. ID. NO: 39) and PhC8 (SEQ. ID. NO: 40). A
reaction solution containing the N-terminal DNA, the C-terminal
DNA, and the primers PhC7 and PhC8 was prepared. The reaction
solution was subjected to PCR under the following thermocycling
conditions: 98.degree. C. for 1 minute; 98.degree. C. for 10
seconds, 52.degree. C. for 30 seconds, and 72.degree. C. for 1
minute and 10 seconds (25 cycles). After the last cycle, the
reacted solution was preserved at 72.degree. C. for 2 minutes.
[0180] The amplified DNA was cloned between the NdeI and XhoI sites
of an expression vector pET-26b so that a His tag is added to the C
terminal. Thus produced was a Ped-CP1-IYRS expression plasmid. The
base sequence of Ped-CP1-IYRS is represented by SEQ. ID. NO:
13.
[0181] The mutation that inactivates editing reaction was
introduced site-specifically by amplifying the whole plasmid by
PCR.
[0182] The expression and purification of the Ped-CP1-IYRS protein
were performed in the same manner as in Example 4. Further, the
expression was confirmed by SDS-PAGE (not shown).
[0183] It should be noted that the mutant with inactivated editing
activity was produced in the same manner (Ped.sup.mu-CP1-IYRS). The
mutation that inactivates the editing reaction domain is the same
as in the case of Ped.sup.mu-N-IYRS described in Example 4. The
Ped.sup.mu-CP1-IYRS expression plasmid was produced in the same
manner as Ped.sup.mu-N-IYRS described in Example 4, except that
Ped-CP1-IYRS was used as a template instead.
Comparative Example 1
Construction of a Ped-AC-IYRS Expression Plasmid
[0184] With use of the genome DNA of P. horikoshii as a template,
DNA coding for the B3/4 domain of P. horikoshii was amplified by
PCR with use of primers PhA1 (SEQ. ID. NO: 41) and PhA2 (SEQ. ID.
NO: 42). The PCR was carried out under the following thermocycling
conditions: 98.degree. C. for 1 minute; 98.degree. C. for 10
seconds, 55.degree. C. for 30 seconds, and 72.degree. C. for 1
minute (25 cycles). After the last cycle, the reacted solution was
preserved at 72.degree. C. for 2 minutes.
[0185] With use of the plasmid A as a template, DNA coding for the
first to 304th amino-acid residues of EcIYRS and DNA coding for the
305th to 424th amino-acid residues of EcIYRS were amplified by PCR
with use of primers PhA3 (SEQ. ID. NO: 43) and PhA4 (SEQ. ID. NO:
44) and by PCR with use of primers PhA5 (SEQ. ID. NO: 45) and PhA6
(SEQ. ID. NO: 46).
[0186] Next, a reaction solution containing the PCR-amplified DNA
coding for the B3/4 domain of P. horikoshii, the PCR-amplified DNA
coding for the N (1-304) and C (305-424) terminals of EcIYRS, and
primers PhA7 (SEQ. ID. NO: 47) and PhA8 (SEQ. ID. NO: 48) was
prepared, and overlap PCR was carried out, whereby a DNA fragment
coding for a fusion protein in which the B1, B2, and B3/4 domains
of P. horikoshii had been inserted into the alpha-helical domain
(AC) of EcIYRS was amplified.
[0187] The amplified DNA was cloned between the NdeI and XhoI sites
of an expression vector pET-26b so that a His tag is added to the C
terminal. Thus produced was a Ped-AC-IYRS expression plasmid. The
base sequence of Ped-AC-IYRS is represented by SEQ. ID. NO: 14.
[0188] The mutation that inactivates editing reaction was
introduced site-specifically by amplifying the whole plasmid by
PCR.
[0189] The expression and purification of the Ped-AC-IYRS protein
were performed in the same manner as in Example 4. Further, the
expression was confirmed by SDS-PAGE (not shown).
[0190] It should be noted that the mutant with inactivated editing
activity was produced in the same manner (Ped.sup.mu-AC-IYRS). The
mutation that inactivates the editing reaction domain is the same
as in the case of Ped.sup.mu-N-IYRS described in Example 4. The
Ped.sup.mu-AC-IYRS expression plasmid was produced in the same
manner as Ped.sup.mu-N-IYRS described in Example 4, except that
Ped-AC-IYRS was used as a template instead.
Example 8
Preparation of Amber Suppressor tRNA.sup.Tyr
[0191] Amber suppressor tRNA.sup.Tyr was prepared with use of a T7
RNA polymerase according to a method devised by Nureki et al.
(Nureki O et al., J Mol Biol 236, 710-724 1994).
[0192] The sequence of the anticodon site of Escherichia coli
tRNA.sup.Tyr was made CUA so as to correspond to an amber codon. A
T7 promoter sequence (SEQ. ID. NO: 73) was added upstream of a DNA
sequence serving as a template for tRNA. CCAGG was designed so that
a site corresponding to the CCA terminal of tRNA could be cleaved
by a restriction endonuclease Mva I. The sequence is as short as
120 bases. Therefore, a DNA fragment was amplified by PCR with use
of a combination of two primers without a template, and the
amplified DNA fragment was cloned into a pUC18 vector.
[0193] The DNA fragment including a cloned region was amplified by
PCR with use of M13 forward and M13 reverse primers. The amplified
DNA fragment was cleaved by Mva I so that one terminal is CCA. With
use of the DNA fragment as a template, tRNA was transcribed with
use of a T7 RNA polymerase. The transcription reaction by a T7 RNA
polymerase was performed by incubation in a reaction solution of (a
composition) at 37.degree. C. for 5 hours. When 2 hours had elapsed
since the start of incubation, a T7 RNA polymerase was added in an
amount a tenth as large as the amount of the first T7 RNA
polymerase. The reaction solution was subjected to
phenol/chloroform extraction. After ammonium acetate had been added
as a salt to the extract, an isopropanol precipitation was
performed. The precipitate was dissolved in 2 ml of 10 mM Hepes-Na
(pH 7.5). After the dissolution, the solution was passed through a
PD-10 desalination column (GE Healthcare, Inc.), whereby unreacted
nucleotides were removed. Another ethanol precipitation was
performed. The precipitate was dissolved in a solution containing
10 mM Hepes-Na (pH 7.5) and 2 mM MgCl.sub.2. After denaturation of
tRNA at 80.degree. C. for 2 minutes, tRNA was rewound by slow
cooling.
Example 9
Determination of the Aminoacylation Activity of Ped-CP1-IYRS
[0194] Next, the aminoacylation activity (tyrosylation activity) of
each of the fusion proteins was determined. The determination was
performed in the same manner as in Example 5. The results are shown
in FIG. 5. It should be noted that the activity of each fusion
protein having a mutation introduced into an editing reaction
domain thereof is indicated by a change in activity of EcIYRS due
to insertion of an editing reaction domain.
[0195] As shown in FIG. 5, Ped-CP1-IYRS had little tyrosine added
to tRNA.sup.Tyr.
[0196] Further, in Ped-AC-IYRS, tyrosylation was detected. It
should be noted that there was no decrease in tyrosylation of
EcIYRS to tRNA.sup.Tyr due to a mutant produced in the same manner
as Ped-AC-IYRS, except for insertion of an inactive editing
reaction domain, and tyrosylation was detected as with Ped-AC-IYRS.
That is, in Ped-AC-IYRS, there was no hydrolysis by an editing
reaction domain.
[0197] Next, each of the fusion proteins was assayed for substrate
specificity. Urea-denatured acidic PAGE was performed to check
whether or not each fusion protein recognized 3-iodotyrosine. The
reaction was performed in the same manner as in the aforementioned
determination of the N-terminal fusion proteins except that the
concentration of Ped-CP1-IYRS was 1 mM or 2 mM and the reaction
temperature was 24.degree. C. or 37.degree. C.
[0198] FIG. 6 shows the results from the mutants. As shown in FIG.
6, Ped-CP1-IYRS was observed to recognize 3-iodotyrosine. Under a
reaction condition of 37.degree. C. for 1 minute, an almost
complete shift in tRNA was observed. Further, under a reaction
condition of 24.degree. C., a shift in band was observed even after
a further prolonged period of reaction. Meanwhile, as with EcIYRS,
Ped-AC-IYRS recognized 3-iodotyrosine.
Example 10
Determination of the Hydrolysis Activity of Ped-CP1-IYRS and
Ped-N-IYRS with Respect to Tyrosyl tRNA
[0199] Next, Ped-CP1-IYRS, which had not tyrosylated tRNA.sup.Tyr
in aminoacylation in Example 9, was checked for its hydrolysis
activity with respect to tyrosyl tRNA. Further, Ped-N-IYRS, which
had been produced in Example 4, was studied, too.
[0200] Under the same conditions as in the determination of the
aminoacylation activity of the N-terminal fusion protein,
[.sup.14C]-tyrosyl tRNA.sup.Tyr was produced with use of a
wild-type EcTyrRS as an enzyme. After 30 minutes of reaction, the
protein was removed by phenol/chloroform treatment, and
[.sup.14C]-tyrosyl tRNA.sup.Tyr was precipitated by ethanol
precipitation. In order to inhibit a naturally-occurring
hydrolysis, the resultant precipitate was dissolved in a 10 mM
sodium citrate buffer solution (pH 4.5).
[0201] The hydrolysis reaction was performed by adding 2.2 mM
[.sup.14C]-tyrosyl tRNA.sup.Tyr and 50 nM Ped-N-IYRS or
Ped-CP1-IYRS to a buffer solution (100 mM Tris-Cl (pH 7.5), 15 mM
MgCl.sub.2). As with the activity determination of aminoacylation,
the remaining [.sup.14C]-tyrosyl tRNA.sup.Tyr was quantified by a
liquid scintillation counter.
[0202] FIG. 7 shows the results of the hydrolysis activity of
Ped-N-IYRS and Ped-CP1-IYRS.
[0203] As shown in FIG. 7, both of the mutants exhibited hydrolysis
activity. Further, Ped-CP1-IYRS exhibited higher hydrolysis
activity than Ped-N-IYRS. It seemed that tyrosyl tRNA can be
hydrolyzed more efficiently when the editing reaction domain is
inserted into the CP1 domain than when the editing reaction domain
is at the N terminal.
[0204] Next, it was confirmed whether or not Ped-CP1-IYRS
introduces tyrosine or 3-iodotyrosine into an amber codon in a
wheat germ cell-free translation system. As the wheat germ
cell-free translation system, an RTS100 wheat germ CECF kit (Roche)
was used, and the protocol that came with the kit was followed.
Since this reaction is performed at 24.degree. C., the structure of
Ped-CP1-IYRS is not disarrayed, so that it is expected that
3-iodotyrosine will be recognized.
[0205] By adding, to this kit, a plasmid into which a gene
controlled by a T7 promoter has been incorporated, the gene can be
expressed. It is known that Escherichia coli-derived EcIYRS and
Escherichia coli tRNA.sup.Tyr are orthogonalized to each other in a
wheat germ translation system (i.e., that EcIYRS does not react
with tRNA inherent in the cells and Escherichia coli tRNA.sup.Tyr
does not react with aaRSs inherent in the cells) (Kiga, D.,
Sakamoto, K., Kodama, K., Kigawa, T., Matsuda, T., Yabuki, T.,
Shirouzu, M., Harada, Y., Nakayama, H., Takio, K., Hasegawa, Y.,
Endo, Y., Hirao, I., Yokoyama, S., An engineered Escherichia coli
tyrosyl-tRNA synthetase for site-specific incorporation of an
unnatural amino acid into proteins in eukaryotic translation and
its application in a wheat germ cell-free system. Proc Natl Acad
Sci USA, 2002, 99, 9715-9720).
[0206] As a reporter protein to be expressed, GST
(glutathione-5-transferase) into which an amber codon has been
introduced was used. The GST gene has a redundant sequence added
upstream thereof, and the redundant sequence has the amber codon
introduced thereinto (GST (Am)) (SEQ. ID. NO: 49) (donated from Dr.
Kobayashi of RIKEN). A DNA fragment coding for GST (Am) was
amplified by PCR, and was cloned at the EcoRV-XhoI site of a vector
pEU3-N11 (TOYOBO Co., Ltd.). When EcIYRS and Escherichia coli amber
suppressor tRNA are added to the cell-free translation system,
tyrosine is introduced into the amber codon, and the GST protein is
translated. That is, the aminoacylation activity of EcIYRS can be
estimated by the amount of the GST protein.
[0207] To a reaction solution included in the wheat germ cell-free
translation system kit, 5 mM Escherichia coli amber suppressor
tRNA, 1 mM 3-iodotyrosine, 2 mM aaRS, and 40 ng/.mu.l of a plasmid
coding for GST (Am) were added, and then were allowed to react at
24.degree. C. for 6 hours. The GST protein thus translated was
detected by western blotting with use of GST antibodies.
[0208] FIG. 8 shows the results of western blotting.
[0209] As shown in FIG. 8, Ped-CP1-IYRS did not express GST at all
in the absence of 3-iodotyrosine (Lane 8). This shows that the
editing reaction domain of Ped-CP1-IYRS functions appropriately in
a translation system. Further, in the presence of 3-iodotyrosine,
Ped-CP1-IYRS expressed the same level of GST as EcIYRS. That is,
there was no decrease in aminoacylation activity due to insertion
of the editing reaction domain. Therefore, Ped-CP1-IYRS could
achieve specific recognition with respect to 3-iodotyrosine.
[0210] Ped.sup.mu-CP1-IYRS exhibited a band of GST in the absence
of 3-iodotyrosine as with EcIYRS, and in addition, expressed the
same level of GST as EcIYRS in the presence of 3-iodotyrosine.
[0211] It should be noted that Ped-CP1-IYRS has a linker,
represented by SEQ. ID. NO: 50, which has been inserted between the
Rossman-fold domain and the N-terminal side of the editing reaction
peptide and a linker, represented by SEQ. ID. NO: 51, which has
been inserted the Rossman-fold domain and the C-terminal side.
These linkers have been inserted in accordance with the sequences
of the primers used in the aforementioned overlap PCR. It was found
that substitution of linkers in Ped-CP1-IYRS has an influence on
the activity to specifically recognize 3-iodotyrosine and
synthesize aminoacylated tRNA. Among such Ped-CP1-IYRSs, a
Ped-CP1-IYRS in which a linker represented by SEQ. ID. NO: 50 is
used at the N-terminal side and a linker represented by SEQ. ID.
NO: 51 is used at the C-terminal side exhibited the highest
activity.
Example 11
Site-Specific Introduction of Iodotyrosine into Proteins with Use
of Ped-CP1-IYRS in Cultured Mammalian Cells
[0212] In order to further verify the usefulness of Ped-CP1-IYRS,
an experiment for introducing iodotyrosine into proteins with use
of Ped-CP1-IYRS in cultured mammalian cells was conducted. The
experiment was all conducted according to the procedures and
methods described in "Sakamoto, K., Hayashi, A., Sakamoto, A.,
Kiga, D., Nakayama, H., Soma, A., Kobayashi, T., Kitabatake, M.,
Takio, T., Saito, K., Shirouzu, M., Hirao, I., and Yokoyama, S.,
Site-specific incorporation of an unnatural amino acid into
proteins in mammalian cells, Nucleic Acids Research 30, 4692-4699,
2002". In expressing Ped-CP1-IYRS in cultured mammalian cells (CHO
cells), such methods for expressing TyrRS and IYRS as described in
the above document were used without modification. Therefore, the
expressed Ped-CP1-IYRS has a FLAG tag added to the C terminal.
[0213] The 32nd codon of the RAS gene was substituted with an amber
codon (Am32), and an attempt to introduce iodotyrosine (IY) into
the position was made. It should be noted that a full-length RAS
protein is expressed when some sort of amino acid has been
introduced into the position. Every protein thus forcibly expressed
has a FLAG tag added thereto, and the expression of proteins was
detected by western blotting with use of anti-FLAG antibodies. The
results are shown in FIG. 9. In FIG. 9, Bands A, B, and C
correspond to Ped-CP1-IYRS, IYRS or Escherichia coli TyrRS, and RAS
proteins, respectively.
[0214] First, a control experiment was conducted to express a RAS
gene including no amber codon (Lane 2) and confirm the position of
a full-length RAS protein on a western blot (Band C). Each of Lanes
3 and 4 shows that a full-length RAS is expressed also when
Escherichia coli TyrRS is expressed. The TyrRS recognizes not
iodotyrosine but a normal tyrosine, and as such, has tyrosine
introduced into the amber site thereof, regardless of whether IY
has been added to the medium (IY+) or not (IY-). See the case of
expression of a mutant IYRS of TyrRS that recognizes iodotyrosine
(Lane 5). In the presence of iodotyrosine, the amino acid is
introduced into the amber site, with the result that a full-length
RAS is expressed. It should be noted here that, as described in the
document above, the amino acid that IYRS introduces into its amber
site at the time of addition of iodotyrosine is iodotyrosine.
However, IYRS still has an affinity to tyrosine. For this reason,
in the absence of iodotyrosine, tyrosine is introduced into the
amber site, with the result that a full-length RAS is expressed
after all (Lane 6).
[0215] See the case of expression of Ped-CP1-IYRS. At the time of
addition of iodotyrosine, a full-length RAS was expressed. This
shows that the mutant has activity to introduce iodotyrosine into
the amber site in the mammalian cells. It is also shown that,
without addition of iodotyrosine, no full-length RAS is expressed,
and as a result, Ped-CP1-IYRS does not introduce tyrosine into the
amber site. That is, as with the results from the wheat germ
cell-free translation system shown in FIG. 8, Ped-CP1-IYRS exhibits
drastically improved specificity to iodotyrosine also the cultured
mammalian cells.
Example 12
Site-Specific Introduction of Iodotyrosine into Proteins with Use
of Ped-CP1-IYRS in Cultured Drosophila Cells
[0216] In order to further verify the usefulness of Ped-CP1-IYRS,
an experiment for introducing iodotyrosine into proteins with use
of Ped-CP1-IYRS in cultured drosophila cells was conducted.
[0217] In expressing Ped-CP1-IYRS in cultured drosophila cells (S2
cells), a commercially available expression vector pMT/V5-His A
(Invitrogen Corporation) was used. As a result, the expressed
Ped-CP1-IYRS has an HA tag added to the C terminal. In expressing
Bacillus stearothermophilus-derived suppressor tRNA.sup.Tyr in the
S2 cells, a U6 promoter (DU6-2 promoter) described in "Wakiyama M.,
Matsumoto T., Yokoyama S., Drosophila U6 promoter-driven short
hairpin RNAs effectively induce RNA interference in Schneider 2
cells, Biochemical and Biophysical Research Communications 331,
1163-1170, 2005" was used upstream of a suppressor tRNA.sup.Tyr
sequence described in "Sakamoto, K. et al., Nucleic Acids Research
30, 4692-4699, 2002".
[0218] The 91st codon of the lacZ gene was substituted with an
amber codon (LacZ (UAG)), and an attempt to introduce iodotyrosine
(IY) into the position was made. It should be noted that when some
sort of amino acid has been introduced into the position, a
full-length LacZ protein is expressed to exhibit
.beta.-galactosidase activity. The results are shown in Table
1.
[0219] First, a control experiment was conducted to express IYRS
and confirm the .beta.-galactosidase activity of a full-length LacZ
protein. In the case of use of LacZ (UAG) as LacZ, LacZ (UAG)
exhibited activity at 17.4% of the expression level of the
wild-type LacZ (LacZ WT), which proved the usefulness of an
iodotyrosine introduction system in cultured drosophila cells.
[0220] Next, see the case of expression of Ped-CP1-IYRS. At the
time of addition of iodotyrosine, a full-length LacZ was expressed.
This shows that the mutant has activity to introduce iodotyrosine
into the amber site in the S2 cells. Meanwhile, without addition of
iodotyrosine, the expression level of full-length LacZ proteins
decreased to approximately 4% compared with the time of addition of
iodotyrosine. This shows that Ped-CP1-IYRS hardly introduces
tyrosine into the amber site.
[0221] That is, in addition to the results from the wheat germ
cell-free translation system in FIG. 8 and the results from the
cultured mammalian cells in FIG. 9, Ped-CP1-IYRS exhibits
drastically improved specificity to iodotyrosine also in the
drosophila cells. It was also shown that in an experimental system
using S2 cells, Ped-CP1-IYRS exhibits not only specificity but also
is comparable in activity to IYRS in terms of iodotyrosine
introduction efficiency.
TABLE-US-00001 TABLE 1 LacZ LacZ WT LacZ(UAG) LacZ(UAG) LacZ(UAG)
aaRS IYRS IYRS Ped-CP1-IYRS Ped-CP1-IYRS IY -- 1 mM 1 mM -- % 100.0
17.4 15.9 0.7
[0222] As described above, a polypeptide according to the present
invention is a polypeptide having aminoacyl-tRNA synthetase
activity, the polypeptide including: an altered polypeptide
obtained by altering an arginyl-tRNA synthetase, a cysteinyl-tRNA
synthetase, a methidnyl-tRNA synthetase, a glutaminyl-tRNA
synthetase, a glutamyl-tRNA synthetase, a lysyl-tRNA synthetase, a
tyrosyl-tRNA synthetase, or a tryptophanyl-tRNA synthetase so that
an unnatural amino acid is recognized; and an editing polypeptide
containing an editing reaction active site derived from a
phenylalanyl-tRNA synthetase, a leucyl-tRNA synthetase, an
isoleucyl-tRNA synthetase, a valyl-tRNA synthetase, an alanyl-tRNA
synthetase, a prolyl-tRNA synthetase, or a threonyl-tRNA
synthetase, the editing polypeptide having been either inserted
between a Rossman-fold N domain and a Rossman-fold C domain that
exist in the altered polypeptide, or bound to an N terminal of the
altered polypeptide. This brings about an effect of high
specificity to an amino acid to be recognized.
[0223] The present invention makes it possible to provide an aaRS
that exhibits high specificity to an amino acid to be recognized,
and as such, makes it possible to produce a protein with various
functions by using an unnatural amino acid. Therefore, the present
invention can be applied in the field of biochemistry and the drug
industry such as the industry for development of new drugs.
[0224] The concrete embodiments and examples of implementation
discussed in the foregoing detailed explanation serve solely to
illustrate the technical details of the present invention, which
should not be narrowly interpreted within the limits of such
embodiments and concrete examples, but rather may be applied in
many variations within the spirit of the present invention,
provided such variations do not exceed the scope of the patent
claims set forth below.
Sequence CWU 1
1
731424PRTEscherichia coli 1Met Ala Ser Ser Asn Leu Ile Lys Gln Leu
Gln Glu Arg Gly Leu Val1 5 10 15Ala Gln Val Thr Asp Glu Glu Ala Leu
Ala Glu Arg Leu Ala Gln Gly 20 25 30Pro Ile Ala Leu Val Cys Gly Phe
Asp Pro Thr Ala Asp Ser Leu His 35 40 45Leu Gly His Leu Val Pro Leu
Leu Cys Leu Lys Arg Phe Gln Gln Ala 50 55 60Gly His Lys Pro Val Ala
Leu Val Gly Gly Ala Thr Gly Leu Ile Gly65 70 75 80Asp Pro Ser Phe
Lys Ala Ala Glu Arg Lys Leu Asn Thr Glu Glu Thr 85 90 95Val Gln Glu
Trp Val Asp Lys Ile Arg Lys Gln Val Ala Pro Phe Leu 100 105 110Asp
Phe Asp Cys Gly Glu Asn Ser Ala Ile Ala Ala Asn Asn Tyr Asp 115 120
125Trp Phe Gly Asn Met Asn Val Leu Thr Phe Leu Arg Asp Ile Gly Lys
130 135 140His Phe Ser Val Asn Gln Met Ile Asn Lys Glu Ala Val Lys
Gln Arg145 150 155 160Leu Asn Arg Glu Asp Gln Gly Ile Ser Phe Thr
Glu Phe Ser Tyr Asn 165 170 175Leu Leu Gln Gly Tyr Asp Phe Ala Cys
Leu Asn Lys Gln Tyr Gly Val 180 185 190Val Leu Cys Ile Gly Gly Ser
Asp Gln Trp Gly Asn Ile Thr Ser Gly 195 200 205Ile Asp Leu Thr Arg
Arg Leu His Gln Asn Gln Val Phe Gly Leu Thr 210 215 220Val Pro Leu
Ile Thr Lys Ala Asp Gly Thr Lys Phe Gly Lys Thr Glu225 230 235
240Gly Gly Ala Val Trp Leu Asp Pro Lys Lys Thr Ser Pro Tyr Lys Phe
245 250 255Tyr Gln Phe Trp Ile Asn Thr Ala Asp Ala Asp Val Tyr Arg
Phe Leu 260 265 270Lys Phe Phe Thr Phe Met Ser Ile Glu Glu Ile Asn
Ala Leu Glu Glu 275 280 285Glu Asp Lys Asn Ser Gly Lys Ala Pro Arg
Ala Gln Tyr Val Leu Ala 290 295 300Glu Gln Val Thr Arg Leu Val His
Gly Glu Glu Gly Leu Gln Ala Ala305 310 315 320Lys Arg Ile Thr Glu
Cys Leu Phe Ser Gly Ser Leu Ser Ala Leu Ser 325 330 335Glu Ala Asp
Phe Glu Gln Leu Ala Gln Asp Gly Val Pro Met Val Glu 340 345 350Met
Glu Lys Gly Ala Asp Leu Met Gln Ala Leu Val Asp Ser Glu Leu 355 360
365Gln Pro Ser Arg Gly Gln Ala Arg Lys Thr Ile Ala Ser Asn Ala Ile
370 375 380Thr Ile Asn Gly Glu Lys Gln Ser Asp Pro Glu Tyr Phe Phe
Lys Glu385 390 395 400Glu Asp Arg Leu Phe Gly Arg Phe Thr Leu Leu
Arg Arg Gly Lys Lys 405 410 415Asn Tyr Cys Leu Ile Cys Trp Lys
4202194PRTPyrococcus horikoshii 2Glu Val Lys Lys Ser Asn Val Thr
Val Tyr Val Asp Glu Lys Leu Lys1 5 10 15Asp Ile Arg Pro Tyr Gly Val
Tyr Ala Ile Val Glu Gly Leu Arg Leu 20 25 30Asp Glu Asp Ser Leu Ser
Gln Met Ile Gln Leu Gln Glu Lys Ile Ala 35 40 45Leu Thr Phe Gly Arg
Arg Arg Arg Glu Val Ala Ile Gly Ile Phe Asp 50 55 60Phe Asp Lys Ile
Lys Pro Pro Ile Tyr Tyr Lys Ala Ala Glu Lys Thr65 70 75 80Glu Lys
Phe Ala Pro Leu Gly Tyr Lys Glu Glu Met Thr Leu Glu Glu 85 90 95Ile
Leu Glu Lys His Glu Lys Gly Arg Glu Tyr Gly His Leu Ile Lys 100 105
110Asp Lys Gln Phe Tyr Pro Leu Leu Ile Asp Ser Glu Gly Asn Val Leu
115 120 125Ser Met Pro Pro Ile Ile Asn Ser Glu Phe Thr Gly Arg Val
Thr Thr 130 135 140Asp Thr Lys Asn Val Phe Ile Asp Val Thr Gly Trp
Lys Leu Glu Lys145 150 155 160Val Met Leu Ala Leu Asn Val Met Val
Thr Ala Leu Ala Glu Arg Gly 165 170 175Gly Lys Ile Arg Ser Val Arg
Val Val Tyr Lys Asp Phe Glu Ile Glu 180 185 190Thr
Pro3627PRTArtificial SequenceDescription of Artificial
SequenceP.horikoshii-E.coli 3Met Ala Ser Ser Asn Leu Ile Lys Gln
Leu Gln Glu Arg Gly Leu Val1 5 10 15Ala Gln Val Thr Asp Glu Glu Ala
Leu Ala Glu Arg Leu Ala Gln Gly 20 25 30Pro Ile Ala Leu Val Cys Gly
Phe Asp Pro Thr Ala Asp Ser Leu His 35 40 45Leu Gly His Leu Val Pro
Leu Leu Cys Leu Lys Arg Phe Gln Gln Ala 50 55 60Gly His Lys Pro Val
Ala Leu Val Gly Gly Ala Thr Gly Leu Ile Gly65 70 75 80Asp Pro Ser
Phe Lys Ala Ala Glu Arg Lys Leu Asn Thr Glu Glu Thr 85 90 95Val Gln
Glu Trp Val Asp Lys Ile Arg Lys Gln Val Ala Pro Phe Leu 100 105
110Asp Phe Asp Cys Gly Glu Asn Ser Ala Ile Ala Ala Asn Asn Tyr Asp
115 120 125Trp Phe Gly Asn Met Asn Val Leu Thr Phe Leu Arg Asp Ile
Gly Lys 130 135 140His Phe Ser Val Asn Gln Met Ile Asn Lys Glu Ala
Val Lys Gln Arg145 150 155 160Leu Asn Arg Glu Asp Gln Glu Val Lys
Lys Ser Asn Val Thr Val Tyr 165 170 175Val Asp Glu Lys Leu Lys Asp
Ile Arg Pro Tyr Gly Val Tyr Ala Ile 180 185 190Val Glu Gly Leu Arg
Leu Asp Glu Asp Ser Leu Ser Gln Met Ile Gln 195 200 205Leu Gln Glu
Lys Ile Ala Leu Thr Phe Gly Arg Arg Arg Arg Glu Val 210 215 220Ala
Ile Gly Ile Phe Asp Phe Asp Lys Ile Lys Pro Pro Ile Tyr Tyr225 230
235 240Lys Ala Ala Glu Lys Thr Glu Lys Phe Ala Pro Leu Gly Tyr Lys
Glu 245 250 255Glu Met Thr Leu Glu Glu Ile Leu Glu Lys His Glu Lys
Gly Arg Glu 260 265 270Tyr Gly His Leu Ile Lys Asp Lys Gln Phe Tyr
Pro Leu Leu Ile Asp 275 280 285Ser Glu Gly Asn Val Leu Ser Met Pro
Pro Ile Ile Asn Ser Glu Phe 290 295 300Thr Gly Arg Val Thr Thr Asp
Thr Lys Asn Val Phe Ile Asp Val Thr305 310 315 320Gly Trp Lys Leu
Glu Lys Val Met Leu Ala Leu Asn Val Met Val Thr 325 330 335Ala Leu
Ala Glu Arg Gly Gly Lys Ile Arg Ser Val Arg Val Val Tyr 340 345
350Lys Asp Phe Glu Ile Glu Thr Pro Gly Ser Ala Ser Gly Pro Ala Ser
355 360 365Ala Gly Ile Ser Phe Thr Glu Phe Ser Tyr Asn Leu Leu Gln
Gly Tyr 370 375 380Asp Phe Ala Cys Leu Asn Lys Gln Tyr Gly Val Val
Leu Cys Ile Gly385 390 395 400Gly Ser Asp Gln Trp Gly Asn Ile Thr
Ser Gly Ile Asp Leu Thr Arg 405 410 415Arg Leu His Gln Asn Gln Val
Phe Gly Leu Thr Val Pro Leu Ile Thr 420 425 430Lys Ala Asp Gly Thr
Lys Phe Gly Lys Thr Glu Gly Gly Ala Val Trp 435 440 445Leu Asp Pro
Lys Lys Thr Ser Pro Tyr Lys Phe Tyr Gln Phe Trp Ile 450 455 460Asn
Thr Ala Asp Ala Asp Val Tyr Arg Phe Leu Lys Phe Phe Thr Phe465 470
475 480Met Ser Ile Glu Glu Ile Asn Ala Leu Glu Glu Glu Asp Lys Asn
Ser 485 490 495Gly Lys Ala Pro Arg Ala Gln Tyr Val Leu Ala Glu Gln
Val Thr Arg 500 505 510Leu Val His Gly Glu Glu Gly Leu Gln Ala Ala
Lys Arg Ile Thr Glu 515 520 525Cys Leu Phe Ser Gly Ser Leu Ser Ala
Leu Ser Glu Ala Asp Phe Glu 530 535 540Gln Leu Ala Gln Asp Gly Val
Pro Met Val Glu Met Glu Lys Gly Ala545 550 555 560Asp Leu Met Gln
Ala Leu Val Asp Ser Glu Leu Gln Pro Ser Arg Gly 565 570 575Gln Ala
Arg Lys Thr Ile Ala Ser Asn Ala Ile Thr Ile Asn Gly Glu 580 585
590Lys Gln Ser Asp Pro Glu Tyr Phe Phe Lys Glu Glu Asp Arg Leu Phe
595 600 605Gly Arg Phe Thr Leu Leu Arg Arg Gly Lys Lys Asn Tyr Cys
Leu Ile 610 615 620Cys Trp Lys62541272DNAEscherichia coli
4atggcaagca gtaacttgat taaacaattg caagagcggg ggctggtagc ccaggtgacg
60gacgaggaag cgttagcaga gcgactggcg caaggcccga tcgcgctcgt ttgcggcttc
120gatcctaccg ctgacagctt gcatttgggg catcttgttc cattgttatg
cctgaaacgc 180ttccagcagg cgggccacaa gccggttgcg ctggtaggcg
gcgcgacggg tctgattggc 240gacccgagct tcaaagctgc cgagcgtaag
ctgaacaccg aagaaactgt tcaggagtgg 300gtggacaaaa tccgtaagca
ggttgccccg ttcctcgatt tcgactgtgg agaaaactct 360gctatcgcgg
cgaacaacta tgactggttc ggcaatatga atgtgctgac cttcctgcgc
420gatattggca aacacttctc cgttaaccag atgatcaaca aagaagcggt
taagcagcgt 480ctcaaccgtg aagatcaggg gatttcgttc actgagtttt
cctacaacct gttgcagggt 540tatgacttcg cctgtctgaa caaacagtac
ggtgtggtgc tgtgcattgg tggttctgac 600cagtggggta acatcacttc
tggtatcgac ctgacccgtc gtctgcatca gaatcaggtg 660tttggcctga
ccgttccgct gatcactaaa gcagatggca ccaaatttgg taaaactgaa
720ggcggcgcag tctggttgga tccgaagaaa accagcccgt acaaattcta
ccagttctgg 780atcaacactg cggatgccga cgtttaccgc ttcctgaagt
tcttcacctt tatgagcatt 840gaagagatca acgccctgga agaagaagat
aaaaacagcg gtaaagcacc gcgcgcccag 900tatgtactgg cggagcaggt
gactcgtctg gttcacggtg aagaaggttt acaggcggca 960aaacgtatta
ccgaatgcct gttcagcggt tctttgagtg cgctgagtga agcggacttc
1020gaacagctgg cgcaggacgg cgtaccgatg gttgagatgg aaaagggcgc
agacctgatg 1080caggcactgg tcgattctga actgcaacct tcccgtggtc
aggcacgtaa aactatcgcc 1140tccaatgcca tcaccattaa cggtgaaaaa
cagtccgatc ctgaatactt ctttaaagaa 1200gaagatcgtc tgtttggtcg
ttttacctta ctgcgtcgcg gtaaaaagaa ttactgtctg 1260atttgctgga aa
12725216PRTEscherichia coli 5Val Gln Pro Glu Ile Val Pro Val Gly
Ala Thr Ile Asp Asp Thr Leu1 5 10 15Pro Ile Thr Val Glu Ala Pro Glu
Ala Cys Pro Arg Tyr Leu Gly Arg 20 25 30Val Val Lys Gly Ile Asn Val
Lys Ala Pro Thr Pro Leu Trp Met Lys 35 40 45Glu Lys Leu Arg Arg Cys
Gly Ile Arg Ser Ile Asp Ala Val Val Asp 50 55 60Val Thr Asn Tyr Val
Leu Leu Glu Leu Gly Gln Pro Met His Ala Phe65 70 75 80Asp Lys Asp
Arg Ile Glu Gly Gly Ile Val Val Arg Met Ala Lys Glu 85 90 95Gly Glu
Thr Leu Val Leu Leu Asp Gly Thr Glu Ala Lys Leu Asn Ala 100 105
110Asp Thr Leu Val Ile Ala Asp His Asn Lys Ala Leu Ala Met Gly Gly
115 120 125Ile Phe Gly Gly Glu His Ser Gly Val Asn Asp Glu Thr Gln
Asn Val 130 135 140Leu Leu Glu Cys Ala Phe Phe Ser Pro Leu Ser Ile
Thr Gly Arg Ala145 150 155 160Arg Arg His Gly Leu His Thr Asp Ala
Ser His Arg Tyr Glu Arg Gly 165 170 175Val Asp Pro Ala Leu Gln His
Lys Ala Met Glu Arg Ala Thr Arg Leu 180 185 190Leu Ile Asp Ile Cys
Gly Gly Glu Ala Gly Pro Val Ile Asp Ile Thr 195 200 205Asn Glu Ala
Thr Leu Pro Lys Arg 210 2156648DNAEscherichia coli 6gttcaaccgg
aaatcgttcc ggttggtgcg accatcgacg acacgctgcc gattacagtc 60gaagcgccgg
aagcctgccc gcgttatctt ggccgtgtgg taaaaggcat taacgttaaa
120gcgccaactc cgctgtggat gaaagaaaaa ctgcgtcgtt gcgggatccg
ttctatcgat 180gcagttgttg acgtcaccaa ctatgtgctg ctcgaactgg
gccagccgat gcacgctttc 240gataaagatc gcattgaagg cggcattgtg
gtgcggatgg cgaaagaggg cgaaacgctg 300gtgctgctcg acggtactga
agcgaagctg aatgctgaca ctctggtcat cgccgaccac 360aacaaggcgc
tggcgatggg cggcatcttc ggtggcgaac actctggcgt gaatgacgaa
420acacaaaacg tgctgctgga atgcgcgttc tttagcccgc tgtctatcac
cggtcgtgct 480cgtcgtcatg gcctgcatac cgatgcgtct caccgttatg
agcgtggcgt tgatccggca 540ctgcagcaca aagcgatgga acgtgcgacc
cgtctgctga tcgacatctg cggtggtgag 600gctggcccgg taattgatat
caccaacgaa gcaacgctgc cgaagcgt 6487582DNAPyrococcus horikoshii
7gaggttaaaa agagtaacgt aacggtttac gttgatgaaa agcttaaaga tataaggcct
60tatggagttt acgcaatagt tgaaggttta aggctcgacg aagattcttt aagtcaaatg
120attcagctac aagaaaagat agcccttaca tttggaagaa gaaggagaga
agtggccata 180ggaatcttcg attttgataa gattaagcca cctatttact
ataaagccgc cgaaaaaact 240gaaaagtttg cccccctggg ctataaagag
gaaatgactc tagaggagat ccttgaaaag 300catgaaaagg gaagggagta
tgggcacctt ataaaggata aacaatttta tccactactt 360attgacagcg
aggggaatgt gctctccatg ccgccaataa tcaactccga gtttacggga
420agagtaacaa cggatacgaa aaatgtcttc atagatgtca cgggatggaa
gcttgagaag 480gtaatgcttg cccttaatgt catggtaact gcattagcag
agcgtggagg taaaataagg 540agcgttaggg ttgtctacaa ggacttcgaa
attgaaaccc ca 5828405PRTThermus thermophilus 8Met Arg Val Pro Phe
Ser Trp Leu Lys Ala Tyr Val Pro Glu Leu Glu1 5 10 15Ser Pro Glu Val
Leu Glu Glu Arg Leu Ala Gly Leu Gly Phe Glu Thr 20 25 30Asp Arg Ile
Glu Arg Val Phe Pro Ile Pro Arg Gly Val Val Phe Ala 35 40 45Arg Val
Leu Glu Ala His Pro Ile Pro Gly Thr Arg Leu Lys Arg Leu 50 55 60Val
Leu Asp Ala Gly Arg Thr Val Glu Val Val Ser Gly Ala Glu Asn65 70 75
80Ala Arg Lys Gly Ile Gly Val Ala Leu Ala Leu Pro Gly Thr Glu Leu
85 90 95Pro Gly Leu Gly Gln Lys Val Gly Glu Arg Val Ile Gln Gly Val
Arg 100 105 110Ser Phe Gly Met Ala Leu Ser Pro Arg Glu Leu Gly Val
Gly Glu Tyr 115 120 125Gly Gly Gly Leu Leu Glu Phe Pro Glu Asp Ala
Leu Pro Pro Gly Thr 130 135 140Pro Leu Ser Glu Ala Trp Pro Glu Glu
Val Val Leu Asp Leu Glu Val145 150 155 160Thr Pro Asn Arg Pro Asp
Ala Leu Gly Leu Leu Gly Leu Ala Arg Asp 165 170 175Leu His Ala Leu
Gly Tyr Ala Leu Val Glu Pro Glu Ala Ala Leu Lys 180 185 190Ala Glu
Ala Leu Pro Leu Pro Phe Ala Leu Lys Val Glu Asp Pro Glu 195 200
205Gly Ala Pro His Phe Thr Leu Gly Tyr Ala Phe Gly Leu Arg Val Ala
210 215 220Pro Ser Pro Leu Trp Met Gln Arg Ala Leu Phe Ala Ala Gly
Met Arg225 230 235 240Pro Ile Asn Asn Val Val Asp Val Thr Asn Tyr
Val Met Leu Glu Arg 245 250 255Ala Gln Pro Met His Ala Phe Asp Leu
Arg Phe Val Gly Glu Gly Ile 260 265 270Ala Val Arg Arg Ala Arg Glu
Gly Glu Arg Leu Lys Thr Leu Asp Gly 275 280 285Val Glu Arg Thr Leu
His Pro Glu Asp Leu Val Ile Ala Gly Trp Arg 290 295 300Gly Glu Glu
Ser Phe Pro Leu Gly Leu Ala Gly Val Met Gly Gly Ala305 310 315
320Glu Ser Glu Val Arg Glu Asp Thr Glu Ala Ile Ala Leu Glu Val Ala
325 330 335Cys Phe Asp Pro Val Ser Ile Arg Lys Thr Ala Arg Arg His
Gly Leu 340 345 350Arg Thr Glu Ala Ser His Arg Phe Glu Arg Gly Val
Asp Pro Leu Gly 355 360 365Gln Val Pro Ala Gln Arg Arg Ala Leu Ser
Leu Leu Gln Ala Leu Ala 370 375 380Gly Ala Arg Val Ala Glu Ala Leu
Leu Glu Ala Gly Ser Pro Lys Pro385 390 395 400Pro Glu Ala Ile Pro
40591215DNAThermus thermophilus 9atgagggtgc ccttctcctg gctaaaagcc
tacgtgcccg agctggaaag ccccgaggtc 60ctggaggagc gcctggcggg cctggggttt
gaaacggacc ggatagagcg ggtcttcccc 120atcccaagag gggtggtctt
cgcccgggtc ctggaggccc accccatccc cggcacccgg 180cttaagcgcc
tggtcctgga cgcgggccgg acggtggaag tggtctcggg ggcggaaaac
240gcccgaaaag gaatcggggt ggccctggcc ctccccggga cggagcttcc
cggcctgggc 300caaaaggtgg gggaacgggt catccaaggg gtgcggtcct
tcggcatggc cctctctccc 360cgggagctcg gggtagggga gtacggcggg
gggcttctgg agttccccga ggacgccctc 420ccccccggca cccccctttc
ggaggcctgg ccggaggagg tggtgctgga cctcgaggtc 480accccgaacc
gcccggacgc cctgggcctt ttgggcctcg cccgggacct ccacgccctg
540ggctacgccc tggtggagcc cgaagcggcc ctgaaggcgg aggcccttcc
cctccccttc 600gccctcaagg tggaggaccc ggagggcgcc ccccacttca
ccctgggcta cgccttcggc 660ctaagggtgg ccccaagccc cctctggatg
cagcgggccc tcttcgccgc gggcatgcgg 720cccatcaaca acgtcgtgga
cgtgaccaac tacgtcatgc tggaaagggc ccagcccatg 780cacgcctttg
acctgcgctt cgtaggagag gggatcgcgg tgcgccgggc gcgggaaggg
840gagcggctta agaccctgga cggggtggaa
agaaccctcc accccgagga cctggtgatc 900gccgggtggc ggggggagga
gagcttcccc ttgggcctcg ccggggtcat gggcggggcg 960gagagcgagg
tccgggagga cacggaggcc atcgccttgg aggtggcctg ctttgacccg
1020gtctccatcc gcaagaccgc ccgccgccac ggcctgcgca ccgaggcgag
ccaccgcttt 1080gagcgggggg tggaccccct gggccaggtc cccgcccaga
ggcgggcctt aagcctcctc 1140caggccctgg cgggggcccg ggtggccgag
gccctcctcg aggcgggaag ccccaagccc 1200ccggaggcca tcccc
1215101926DNAEscherichia coli 10atggttcaac cggaaatcgt tccggttggt
gcgaccatcg acgacacgct gccgattaca 60gtcgaagcgc cggaagcctg cccgcgttat
cttggccgtg tggtaaaagg cattaacgtt 120aaagcgccaa ctccgctgtg
gatgaaagaa aaactgcgtc gttgcgggat ccgttctatc 180gatgcagttg
ttgacgtcac caactatgtg ctgctcgaac tgggccagcc gatgcacgct
240ttcgataaag atcgcattga aggcggcatt gtggtgcgga tggcgaaaga
gggcgaaacg 300ctggtgctgc tcgacggtac tgaagcgaag ctgaatgctg
acactctggt catcgccgac 360cacaacaagg cgctggcgat gggcggcatc
ttcggtggcg aacactctgg cgtgaatgac 420gaaacacaaa acgtgctgct
ggaatgcgcg ttctttagcc cgctgtctat caccggtcgt 480gctcgtcgtc
atggcctgca taccgatgcg tctcaccgtt atgagcgtgg cgttgatccg
540gcactgcagc acaaagcgat ggaacgtgcg acccgtctgc tgatcgacat
ctgcggtggt 600gaggctggcc cggtaattga tatcaccaac gaagcaacgc
tgccgaagcg tatggcaagc 660agtaacttga ttaaacaatt gcaagagcgg
gggctggtag cccaggtgac ggacgaggaa 720gcgttagcag agcgactggc
gcaaggcccg atcgcgctcg tttgcggctt cgatcctacc 780gctgacagct
tgcatttggg gcatcttgtt ccattgttat gcctgaaacg cttccagcag
840gcgggccaca agccggttgc gctggtaggc ggcgcgacgg gtctgattgg
cgacccgagc 900ttcaaagctg ccgagcgtaa gctgaacacc gaagaaactg
ttcaggagtg ggtggacaaa 960atccgtaagc aggttgcccc gttcctcgat
ttcgactgtg gagaaaactc tgctatcgcg 1020gcgaacaact atgactggtt
cggcaatatg aatgtgctga ccttcctgcg cgatattggc 1080aaacacttct
ccgttaacca gatgatcaac aaagaagcgg ttaagcagcg tctcaaccgt
1140gaagatcagg ggatttcgtt cactgagttt tcctacaacc tgttgcaggg
ttatgacttc 1200gcctgtctga acaaacagta cggtgtggtg ctgtgcattg
gtggttctga ccagtggggt 1260aacatcactt ctggtatcga cctgacccgt
cgtctgcatc agaatcaggt gtttggcctg 1320accgttccgc tgatcactaa
agcagatggc accaaatttg gtaaaactga aggcggcgca 1380gtctggttgg
atccgaagaa aaccagcccg tacaaattct accagttctg gatcaacact
1440gcggatgccg acgtttaccg cttcctgaag ttcttcacct ttatgagcat
tgaagagatc 1500aacgccctgg aagaagaaga taaaaacagc ggtaaagcac
cgcgcgccca gtatgtactg 1560gcggagcagg tgactcgtct ggttcacggt
gaagaaggtt tacaggcggc aaaacgtatt 1620accgaatgcc tgttcagcgg
ttctttgagt gcgctgagtg aagcggactt cgaacagctg 1680gcgcaggacg
gcgtaccgat ggttgagatg gaaaagggcg cagacctgat gcaggcactg
1740gtcgattctg aactgcaacc ttcccgtggt caggcacgta aaactatcgc
ctccaatgcc 1800atcaccatta acggtgaaaa acagtccgat cctgaatact
tctttaaaga agaagatcgt 1860ctgtttggtc gttttacctt actgcgtcgc
ggtaaaaaga attactgtct gatttgctgg 1920aaataa 1926112508DNAArtificial
SequenceDescription of Artificial SequenceTed-N-IYRS 11atgagggtgc
ccttctcctg gctaaaagcc tacgtgcccg agctggaaag ccccgaggtc 60ctggaggagc
gcctggcggg cctggggttt gaaacggacc ggatagagcg ggtcttcccc
120atcccaagag gggtggtctt cgcccgggtc ctggaggccc accccatccc
cggcacccgg 180cttaagcgcc tggtcctgga cgcgggccgg acggtggaag
tggtctcggg ggcggaaaac 240gcccgaaaag gaatcggggt ggccctggcc
ctccccggga cggagcttcc cggcctgggc 300caaaaggtgg gggaacgggt
catccaaggg gtgcggtcct tcggcatggc cctctctccc 360cgggagctcg
gggtagggga gtacggcggg gggcttctgg agttccccga ggacgccctc
420ccccccggca cccccctttc ggaggcctgg ccggaggagg tggtgctgga
cctcgaggtc 480accccgaacc gcccggacgc cctgggcctt ttgggcctcg
cccgggacct ccacgccctg 540ggctacgccc tggtggagcc cgaagcggcc
ctgaaggcgg aggcccttcc cctccccttc 600gccctcaagg tggaggaccc
ggagggcgcc ccccacttca ccctgggcta cgccttcggc 660ctaagggtgg
ccccaagccc cctctggatg cagcgggccc tcttcgccgc gggcatgcgg
720cccatcaaca acgtcgtgga cgtgaccaac tacgtcatgc tggaaagggc
ccagcccatg 780cacgcctttg acctgcgctt cgtaggagag gggatcgcgg
tgcgccgggc gcgggaaggg 840gagcggctta agaccctgga cggggtggaa
agaaccctcc accccgagga cctggtgatc 900gccgggtggc ggggggagga
gagcttcccc ttgggcctcg ccggggtcat gggcggggcg 960gagagcgagg
tccgggagga cacggaggcc atcgccttgg aggtggcctg ctttgacccg
1020gtctccatcc gcaagaccgc ccgccgccac ggcctgcgca ccgaggcgag
ccaccgcttt 1080gagcgggggg tggaccccct gggccaggtc cccgcccaga
ggcgggcctt aagcctcctc 1140caggccctgg cgggggcccg ggtggccgag
gccctcctcg aggcgggaag ccccaagccc 1200ccggaggcca tccccggcag
cgcgccgagc ggcatggcaa gcagtaactt gattaaacaa 1260ttgcaagagc
gggggctggt agcccaggtg acggacgagg aagcgttagc agagcgactg
1320gcgcaaggcc cgatcgcgct cgtttgcggc ttcgatccta ccgctgacag
cttgcatttg 1380gggcatcttg ttccattgtt atgcctgaaa cgcttccagc
aggcgggcca caagccggtt 1440gcgctggtag gcggcgcgac gggtctgatt
ggcgacccga gcttcaaagc tgccgagcgt 1500aagctgaaca ccgaagaaac
tgttcaggag tgggtggaca aaatccgtaa gcaggttgcc 1560ccgttcctcg
atttcgactg tggagaaaac tctgctatcg cggcgaacaa ctatgactgg
1620ttcggcaata tgaatgtgct gaccttcctg cgcgatattg gcaaacactt
ctccgttaac 1680cagatgatca acaaagaagc ggttaagcag cgtctcaacc
gtgaagatca ggggatttcg 1740ttcactgagt tttcctacaa cctgttgcag
ggttatgact tcgcctgtct gaacaaacag 1800tacggtgtgg tgctgtgcat
tggtggttct gaccagtggg gtaacatcac ttctggtatc 1860gacctgaccc
gtcgtctgca tcagaatcag gtgtttggcc tgaccgttcc gctgatcact
1920aaagcagatg gcaccaaatt tggtaaaact gaaggcggcg cagtctggtt
ggatccgaag 1980aaaaccagcc cgtacaaatt ctaccagttc tggatcaaca
ctgcggatgc cgacgtttac 2040cgcttcctga agttcttcac ctttatgagc
attgaagaga tcaacgccct ggaagaagaa 2100gataaaaaca gcggtaaagc
accgcgcgcc cagtatgtac tggcggagca ggtgactcgt 2160ctggttcacg
gtgaagaagg tttacaggcg gcaaaacgta ttaccgaatg cctgttcagc
2220ggttctttga gtgcgctgag tgaagcggac ttcgaacagc tggcgcagga
cggcgtaccg 2280atggttgaga tggaaaaggg cgcagacctg atgcaggcac
tggtcgattc tgaactgcaa 2340ccttcccgtg gtcaggcacg taaaactatc
gcctccaatg ccatcaccat taacggtgaa 2400aaacagtccg atcctgaata
cttctttaaa gaagaagatc gtctgtttgg tcgttttacc 2460ttactgcgtc
gcggtaaaaa gaattactgt ctgatttgct ggaaataa 2508121890DNAArtificial
SequenceDescription of Artificial SequencePed-N-IYRS 12atggaggtta
aaaagagtaa cgtaacggtt tacgttgatg aaaagcttaa agatataagg 60ccttatggag
tttacgcaat agttgaaggt ttaaggctcg acgaagattc tttaagtcaa
120atgattcagc tacaagaaaa gatagccctt acatttggaa gaagaaggag
agaagtggcc 180ataggaatct tcgattttga taagattaag ccacctattt
actataaagc cgccgaaaaa 240actgaaaagt ttgcccccct gggctataaa
gaggaaatga ctctagagga gatccttgaa 300aagcatgaaa agggaaggga
gtatgggcac cttataaagg ataaacaatt ttatccacta 360cttattgaca
gcgaggggaa tgtgctctcc atgccgccaa taatcaactc cgagtttacg
420ggaagagtaa caacggatac gaaaaatgtc ttcatagatg tcacgggatg
gaagcttgag 480aaggtaatgc ttgcccttaa tgtcatggta actgcattag
cagagcgtgg aggtaaaata 540aggagcgtta gggttgtcta caaggacttc
gaaattgaaa ccccaggctc cgcctccggc 600cccgcctccg ccggcatggc
aagcagtaac ttgattaaac aattgcaaga gcgggggctg 660gtagcccagg
tgacggacga ggaagcgtta gcagagcgac tggcgcaagg cccgatcgcg
720ctcgtttgcg gcttcgatcc taccgctgac agcttgcatt tggggcatct
tgttccattg 780ttatgcctga aacgcttcca gcaggcgggc cacaagccgg
ttgcgctggt aggcggcgcg 840acgggtctga ttggcgaccc gagcttcaaa
gctgccgagc gtaagctgaa caccgaagaa 900actgttcagg agtgggtgga
caaaatccgt aagcaggttg ccccgttcct cgatttcgac 960tgtggagaaa
actctgctat cgcggcgaac aactatgact ggttcggcaa tatgaatgtg
1020ctgaccttcc tgcgcgatat tggcaaacac ttctccgtta accagatgat
caacaaagaa 1080gcggttaagc agcgtctcaa ccgtgaagat caggggattt
cgttcactga gttttcctac 1140aacctgttgc agggttatga cttcgcctgt
ctgaacaaac agtacggtgt ggtgctgtgc 1200attggtggtt ctgaccagtg
gggtaacatc acttctggta tcgacctgac ccgtcgtctg 1260catcagaatc
aggtgtttgg cctgaccgtt ccgctgatca ctaaagcaga tggcaccaaa
1320tttggtaaaa ctgaaggcgg cgcagtctgg ttggatccga agaaaaccag
cccgtacaaa 1380ttctaccagt tctggatcaa cactgcggat gccgacgttt
accgcttcct gaagttcttc 1440acctttatga gcattgaaga gatcaacgcc
ctggaagaag aagataaaaa cagcggtaaa 1500gcaccgcgcg cccagtatgt
actggcggag caggtgactc gtctggttca cggtgaagaa 1560ggtttacagg
cggcaaaacg tattaccgaa tgcctgttca gcggttcttt gagtgcgctg
1620agtgaagcgg acttcgaaca gctggcgcag gacggcgtac cgatggttga
gatggaaaag 1680ggcgcagacc tgatgcaggc actggtcgat tctgaactgc
aaccttcccg tggtcaggca 1740cgtaaaacta tcgcctccaa tgccatcacc
attaacggtg aaaaacagtc cgatcctgaa 1800tacttcttta aagaagaaga
tcgtctgttt ggtcgtttta ccttactgcg tcgcggtaaa 1860aagaattact
gtctgatttg ctggaaataa 1890131884DNAArtificial SequenceDescription
of Artificial SequencePed-CP1-IYRS 13atggcaagca gtaacttgat
taaacaattg caagagcggg ggctggtagc ccaggtgacg 60gacgaggaag cgttagcaga
gcgactggcg caaggcccga tcgcgctcgt ttgcggcttc 120gatcctaccg
ctgacagctt gcatttgggg catcttgttc cattgttatg cctgaaacgc
180ttccagcagg cgggccacaa gccggttgcg ctggtaggcg gcgcgacggg
tctgattggc 240gacccgagct tcaaagctgc cgagcgtaag ctgaacaccg
aagaaactgt tcaggagtgg 300gtggacaaaa tccgtaagca ggttgccccg
ttcctcgatt tcgactgtgg agaaaactct 360gctatcgcgg cgaacaacta
tgactggttc ggcaatatga atgtgctgac cttcctgcgc 420gatattggca
aacacttctc cgttaaccag atgatcaaca aagaagcggt taagcagcgt
480ctcaaccgtg aagatcagga ggttaaaaag agtaacgtaa cggtttacgt
tgatgaaaag 540cttaaagata taaggcctta tggagtttac gcaatagttg
aaggtttaag gctcgacgaa 600gattctttaa gtcaaatgat tcagctacaa
gaaaagatag cccttacatt tggaagaaga 660aggagagaag tggccatagg
aatcttcgat tttgataaga ttaagccacc tatttactat 720aaagccgccg
aaaaaactga aaagtttgcc cccctgggct ataaagagga aatgactcta
780gaggagatcc ttgaaaagca tgaaaaggga agggagtatg ggcaccttat
aaaggataaa 840caattttatc cactacttat tgacagcgag gggaatgtgc
tctccatgcc gccaataatc 900aactccgagt ttacgggaag agtaacaacg
gatacgaaaa atgtcttcat agatgtcacg 960ggatggaagc ttgagaaggt
aatgcttgcc cttaatgtca tggtaactgc attagcagag 1020cgtggaggta
aaataaggag cgttagggtt gtctacaagg acttcgaaat tgaaacccca
1080ggctccgcct ccggccccgc ctccgccggg atttcgttca ctgagttttc
ctacaacctg 1140ttgcagggtt atgacttcgc ctgtctgaac aaacagtacg
gtgtggtgct gtgcattggt 1200ggttctgacc agtggggtaa catcacttct
ggtatcgacc tgacccgtcg tctgcatcag 1260aatcaggtgt ttggcctgac
cgttccgctg atcactaaag cagatggcac caaatttggt 1320aaaactgaag
gcggcgcagt ctggttggat ccgaagaaaa ccagcccgta caaattctac
1380cagttctgga tcaacactgc ggatgccgac gtttaccgct tcctgaagtt
cttcaccttt 1440atgagcattg aagagatcaa cgccctggaa gaagaagata
aaaacagcgg taaagcaccg 1500cgcgcccagt atgtactggc ggagcaggtg
actcgtctgg ttcacggtga agaaggttta 1560caggcggcaa aacgtattac
cgaatgcctg ttcagcggtt ctttgagtgc gctgagtgaa 1620gcggacttcg
aacagctggc gcaggacggc gtaccgatgg ttgagatgga aaagggcgca
1680gacctgatgc aggcactggt cgattctgaa ctgcaacctt cccgtggtca
ggcacgtaaa 1740actatcgcct ccaatgccat caccattaac ggtgaaaaac
agtccgatcc tgaatacttc 1800tttaaagaag aagatcgtct gtttggtcgt
tttaccttac tgcgtcgcgg taaaaagaat 1860tactgtctga tttgctggaa ataa
1884141914DNAArtificial SequenceDescription of Artificial
SequencePed-AC-IYRS 14atggcaagca gtaacttgat taaacaattg caagagcggg
ggctggtagc ccaggtgacg 60gacgaggaag cgttagcaga gcgactggcg caaggcccga
tcgcgctcgt ttgcggcttc 120gatcctaccg ctgacagctt gcatttgggg
catcttgttc cattgttatg cctgaaacgc 180ttccagcagg cgggccacaa
gccggttgcg ctggtaggcg gcgcgacggg tctgattggc 240gacccgagct
tcaaagctgc cgagcgtaag ctgaacaccg aagaaactgt tcaggagtgg
300gtggacaaaa tccgtaagca ggttgccccg ttcctcgatt tcgactgtgg
agaaaactct 360gctatcgcgg cgaacaacta tgactggttc ggcaatatga
atgtgctgac cttcctgcgc 420gatattggca aacacttctc cgttaaccag
atgatcaaca aagaagcggt taagcagcgt 480ctcaaccgtg aagatcaggg
gatttcgttc actgagtttt cctacaacct gttgcagggt 540tatgacttcg
cctgtctgaa caaacagtac ggtgtggtgc tgtgcattgg tggttctgac
600cagtggggta acatcacttc tggtatcgac ctgacccgtc gtctgcatca
gaatcaggtg 660tttggcctga ccgttccgct gatcactaaa gcagatggca
ccaaatttgg taaaactgaa 720ggcggcgcag tctggttgga tccgaagaaa
accagcccgt acaaattcta ccagttctgg 780atcaacactg cggatgccga
cgtttaccgc ttcctgaagt tcttcacctt tatgagcatt 840gaagagatca
acgccctgga agaagaagat aaaaacagcg gtaaagcacc gcgcgcccag
900tatgtactgg cggaggttaa aaagagtaac gtaacggttt acgttgatga
aaagcttaaa 960gatataaggc cttatggagt ttacgcaata gttgaaggtt
taaggctcga cgaagattct 1020ttaagtcaaa tgattcagct acaagaaaag
atagccctta catttggaag aagaaggaga 1080gaagtggcca taggaatctt
cgattttgat aagattaagc cacctattta ctataaagcc 1140gccgaaaaaa
ctgaaaagtt tgcccccctg ggctataaag aggaaatgac tctagaggag
1200atccttgaaa agcatgaaaa gggaagggag tatgggcacc ttataaagga
taaacaattt 1260tatccactac ttattgacag cgaggggaat gtgctctcca
tgccgccaat aatcaactcc 1320gagtttacgg gaagagtaac aacggatacg
aaaaatgtct tcatagatgt cacgggatgg 1380aagcttgaga aggtaatgct
tgcccttaat gtcatggtaa ctgcattagc agagcgtgga 1440ggtaaaataa
ggagcgttag ggttgtctac aaggacttcg aaattgaaac cccaggctcc
1500gcctccggcc ccgcctccgc cggcgcaccg cgcgcccagt atgtactggc
ggagcaggtg 1560actcgtctgg ttcacggtga agaaggttta caggcggcaa
aacgtattac cgaatgcctg 1620ttcagcggtt ctttgagtgc gctgagtgaa
gcggacttcg aacagctggc gcaggacggc 1680gtaccgatgg ttgagatgga
aaagggcgca gacctgatgc aggcactggt cgattctgaa 1740ctgcaacctt
cccgtggtca ggcacgtaaa actatcgcct ccaatgccat caccattaac
1800ggtgaaaaac agtccgatcc tgaatacttc tttaaagaag aagatcgtct
gtttggtcgt 1860tttaccttac tgcgtcgcgg taaaaagaat tactgtctga
tttgctggaa ataa 19141534DNAArtificial SequenceDescription of
Artificial SequencePrimer EcN1 15gcacgccata tggttcaacc ggaaatcgtt
ccgg 341636DNAArtificial SequenceDescription of Artificial
SequencePrimer EcN2 16gttactgctt gccatacgct tcggcagcgt tgcttc
361736DNAArtificial SequenceDescription of Artificial
SequencePrimer EcN3 17gaagcaacgc tgccgaagcg tatggcaagc agtaac
361831DNAArtificial SequenceDescription of Artificial
SequencePrimer EcN4 18aggtgcctcg agtttccagc aaatcagaca g
311934DNAArtificial SequenceDescription of Artificial
SequencePrimer EcN5 19gcacgccata tggttcaacc ggaaatcgtt ccgg
342031DNAArtificial SequenceDescription of Artificial
SequencePrimer EcN6 20aggtgcctcg agtttccagc aaatcagaca g
312137DNAArtificial SequenceDescription of Artificial
SequencePrimer TtN1 21gccgcccata tgagggtgcc cttctcctgg ctaaaag
372254DNAArtificial SequenceDescription of Artificial
SequencePrimer TtN2 22caagttactg cttgccatgc cgctcggcgc gctgccgggg
atggcctccg gggg 542354DNAArtificial SequenceDescription of
Artificial SequencePrimer TtN3 23cccccggagg ccatccccgg cagcgcgccg
agcggcatgg caagcagtaa cttg 542431DNAArtificial SequenceDescription
of Artificial SequencePrimer TtN4 24aggtgcctcg agtttccagc
aaatcagaca g 312537DNAArtificial SequenceDescription of Artificial
SequencePrimer TtN5 25gccgcccata tgagggtgcc cttctcctgg ctaaaag
372631DNAArtificial SequenceDescription of Artificial
SequencePrimer TtN6 26aggtgcctcg agtttccagc aaatcagaca g
312731DNAArtificial SequenceDescription of Artificial
SequencePrimer PhN1 27cccatatgga ggttaaaaag agtaacgtaa c
312860DNAArtificial SequenceDescription of Artificial
SequencePrimer PhN2 28gttactgctt gccatgccgg cggaggcggg gccggaggcg
gagcctgggg tttcaatttc 602960DNAArtificial SequenceDescription of
Artificial SequencePrimer PhN3 29gaaattgaaa ccccaggctc cgcctccggc
cccgcctccg ccggcatggc aagcagtaac 603031DNAArtificial
SequenceDescription of Artificial SequencePrimer PhN4 30aggtgcctcg
agtttccagc aaatcagaca g 313131DNAArtificial SequenceDescription of
Artificial SequencePrimer PhN5 31cccatatgga ggttaaaaag agtaacgtaa c
313231DNAArtificial SequenceDescription of Artificial
SequencePrimer PhN6 32aggtgcctcg agtttccagc aaatcagaca g
313330DNAArtificial SequenceDescription of Artificial
SequencePrimer PhC1 33caaccgtgaa gatcaggagg ttaaaaagag
303431DNAArtificial SequenceDescription of Artificial
SequencePrimer PhC2 34cagtgaacga aatcccggcg gaggcggggc c
313534DNAArtificial SequenceDescription of Artificial
SequencePrimer PhC3 35cggcgccata tggcaagcag taacttgatt aaac
343630DNAArtificial SequenceDescription of Artificial
SequencePrimer PhC4 36ctctttttaa cctcctgatc ttcacggttg
303731DNAArtificial SequenceDescription of Artificial
SequencePrimer PhC5 37ggccccgcct ccgccgggat ttcgttcact g
313831DNAArtificial SequenceDescription of Artificial
SequencePrimer PhC6 38aggtgcctcg agtttccagc aaatcagaca g
313934DNAArtificial SequenceDescription of Artificial
SequencePrimer PhC7 39cggcgccata tggcaagcag taacttgatt aaac
344031DNAArtificial SequenceDescription of Artificial
SequencePrimer PhC8 40aggtgcctcg agtttccagc aaatcagaca g
314133DNAArtificial SequenceDescription of Artificial
SequencePrimer PhA1 41cagtatgtac tggcggaggt taaaaagagt aac
334230DNAArtificial SequenceDescription of Artificial
SequencePrimer PhA2 42ctgggcgcgc ggtgcgccgg cggaggcggg
304334DNAArtificial SequenceDescription of Artificial
SequencePrimer PhA3 43cggcgccata tggcaagcag taacttgatt aaac
344433DNAArtificial SequenceDescription of Artificial
SequencePrimer PhA4 44gttactcttt ttaacctccg ccagtacata ctg
334530DNAArtificial SequenceDescription of Artificial
SequencePrimer PhA5 45cccgcctccg ccggcgcacc gcgcgcccag
304631DNAArtificial SequenceDescription of Artificial
SequencePrimer PhA6 46aggtgcctcg agtttccagc aaatcagaca g
314734DNAArtificial SequenceDescription of Artificial
SequencePrimer PhA7 47cggcgccata tggcaagcag taacttgatt aaac
344831DNAArtificial SequenceDescription of Artificial
SequencePrimer PhA8
48aggtgcctcg agtttccagc aaatcagaca g 3149738DNAArtificial
SequenceDescription of Artificial SequenceGST(Am) 49atggctagca
tgactggtgg acagcaaatg ggtcgggatc cgggtgcgaa ttctggtgta 60actaagaact
cttagagccc tatactaggt tattggaaaa ttaagggcct tgtgcaaccc
120actcgacttc ttttggaata tcttgaagaa aaatatgaag agcatttgta
tgagcgcgat 180gaaggtgata aatggcgaaa caaaaagttt gaattgggtt
tggagtttcc caatcttcct 240tattatattg atggtgatgt taaattaaca
cagtctatgg ccatcatacg ttatatagct 300gacaagcaca acatgttggg
tggttgtcca aaagagcgtg cagagatttc aatgcttgaa 360ggagcggttt
tggatattag atacggtgtt tcgagaattg catatagtaa agactttgaa
420actctcaaag ttgattttct tagcaagcta cctgaaatgc tgaaaatgtt
cgaagatcgt 480ttatgtcata aaacatattt aaatggtgat catgtaaccc
atcctgactt catgttgtat 540gacgctcttg atgttgtttt atacatggac
ccaatgtgcc tggatgcgtt cccaaaatta 600gtttgtttta aaaaacgtat
tgaagctatc ccacaaattg ataagtactt gaaatccagc 660aagtatatag
catggccttt gcagggctgg caagccacgt ttggtggtgg cgaccatcct
720ccaaaatcgg attaataa 7385015PRTArtificial SequenceDescription of
Artificial SequencelinkerN 50Gln Arg Leu Asn Arg Glu Asp Gln Glu
Val Lys Lys Ser Asn Val1 5 10 155122PRTArtificial
SequenceDescription of Artificial SequencelinkerC 51Glu Ile Glu Thr
Pro Gly Ser Ala Ser Gly Pro Ala Ser Ala Gly Ile1 5 10 15Ser Phe Thr
Phe Ser Tyr 2052795PRTEscherichia coli 52Met Lys Phe Ser Glu Leu
Trp Leu Arg Glu Trp Val Asn Pro Ala Ile1 5 10 15Asp Ser Asp Ala Leu
Ala Asn Gln Ile Thr Met Ala Gly Leu Glu Val 20 25 30Asp Gly Val Glu
Pro Val Ala Gly Ser Phe His Gly Val Val Val Gly 35 40 45Glu Val Val
Glu Cys Ala Gln His Pro Asn Ala Asp Lys Leu Arg Val 50 55 60Thr Lys
Val Asn Val Gly Gly Asp Arg Leu Leu Asp Ile Val Cys Gly65 70 75
80Ala Pro Asn Cys Arg Gln Gly Leu Arg Val Ala Val Ala Thr Ile Gly
85 90 95Ala Val Leu Pro Gly Asp Phe Lys Ile Lys Ala Ala Lys Leu Arg
Gly 100 105 110Glu Pro Ser Glu Gly Met Leu Cys Ser Phe Ser Glu Leu
Gly Ile Ser 115 120 125Asp Asp His Ser Gly Ile Ile Glu Leu Pro Ala
Asp Ala Pro Ile Gly 130 135 140Thr Asp Ile Arg Glu Tyr Leu Lys Leu
Asp Asp Asn Thr Ile Glu Ile145 150 155 160Ser Val Thr Pro Asn Arg
Ala Asp Cys Leu Gly Ile Ile Gly Val Ala 165 170 175Arg Asp Val Ala
Val Leu Asn Gln Leu Pro Leu Val Gln Pro Glu Ile 180 185 190Val Pro
Val Gly Ala Thr Ile Asp Asp Thr Leu Pro Ile Thr Val Glu 195 200
205Ala Pro Glu Ala Cys Pro Arg Tyr Leu Gly Arg Val Val Lys Gly Ile
210 215 220Asn Val Lys Ala Pro Thr Pro Leu Trp Met Lys Glu Lys Leu
Arg Arg225 230 235 240Cys Gly Ile Arg Ser Ile Asp Ala Val Val Asp
Val Thr Asn Tyr Val 245 250 255Leu Leu Glu Leu Gly Gln Pro Met His
Ala Phe Asp Lys Asp Arg Ile 260 265 270Glu Gly Gly Ile Val Val Arg
Met Ala Lys Glu Gly Glu Thr Leu Val 275 280 285Leu Leu Asp Gly Thr
Glu Ala Lys Leu Asn Ala Asp Thr Leu Val Ile 290 295 300Ala Asp His
Asn Lys Ala Leu Ala Met Gly Gly Ile Phe Gly Gly Glu305 310 315
320His Ser Gly Val Asn Asp Glu Thr Gln Asn Val Leu Leu Glu Cys Ala
325 330 335Phe Phe Ser Pro Leu Ser Ile Thr Gly Arg Ala Arg Arg His
Gly Leu 340 345 350His Thr Asp Ala Ser His Arg Tyr Glu Arg Gly Val
Asp Pro Ala Leu 355 360 365Gln His Lys Ala Met Glu Arg Ala Thr Arg
Leu Leu Ile Asp Ile Cys 370 375 380Gly Gly Glu Ala Gly Pro Val Ile
Asp Ile Thr Asn Glu Ala Thr Leu385 390 395 400Pro Lys Arg Ala Thr
Ile Thr Leu Arg Arg Ser Lys Leu Asp Arg Leu 405 410 415Ile Gly His
His Ile Ala Asp Glu Gln Val Thr Asp Ile Leu Arg Arg 420 425 430Leu
Gly Cys Glu Val Thr Glu Gly Lys Asp Glu Trp Gln Ala Val Ala 435 440
445Pro Ser Trp Arg Phe Asp Met Glu Ile Glu Glu Asp Leu Val Glu Glu
450 455 460Val Ala Arg Val Tyr Gly Tyr Asn Asn Ile Pro Asp Glu Pro
Val Gln465 470 475 480Ala Ser Leu Ile Met Gly Thr His Arg Glu Ala
Asp Leu Ser Leu Lys 485 490 495Arg Val Lys Thr Leu Leu Asn Asp Lys
Gly Tyr Gln Glu Val Ile Thr 500 505 510Tyr Ser Phe Val Asp Pro Lys
Val Gln Gln Met Ile His Pro Gly Val 515 520 525Glu Ala Leu Leu Leu
Pro Ser Pro Ile Ser Val Glu Met Ser Ala Met 530 535 540Arg Leu Ser
Leu Trp Thr Gly Leu Leu Ala Thr Val Val Tyr Asn Gln545 550 555
560Asn Arg Gln Gln Asn Arg Val Arg Ile Phe Glu Ser Gly Leu Arg Phe
565 570 575Val Pro Asp Thr Gln Ala Pro Leu Gly Ile Arg Gln Asp Leu
Met Leu 580 585 590Ala Gly Val Ile Cys Gly Asn Arg Tyr Glu Glu His
Trp Asn Leu Ala 595 600 605Lys Glu Thr Val Asp Phe Tyr Asp Leu Lys
Gly Asp Leu Glu Ser Val 610 615 620Leu Asp Leu Thr Gly Lys Leu Asn
Glu Val Glu Phe Arg Ala Glu Ala625 630 635 640Asn Pro Ala Leu His
Pro Gly Gln Ser Ala Ala Ile Tyr Leu Lys Gly 645 650 655Glu Arg Ile
Gly Phe Val Gly Val Val His Pro Glu Leu Glu Arg Lys 660 665 670Leu
Asp Leu Asn Gly Arg Thr Leu Val Phe Glu Leu Glu Trp Asn Lys 675 680
685Leu Ala Asp Arg Val Val Pro Gln Ala Arg Glu Ile Ser Arg Phe Pro
690 695 700Ala Asn Arg Arg Asp Ile Ala Val Val Val Ala Glu Asn Val
Pro Ala705 710 715 720Ala Asp Ile Leu Ser Glu Cys Lys Lys Val Gly
Val Asn Gln Val Val 725 730 735Gly Val Asn Leu Phe Asp Val Tyr Arg
Gly Lys Gly Val Ala Glu Gly 740 745 750Tyr Lys Ser Leu Ala Ile Ser
Leu Ile Leu Gln Asp Thr Ser Arg Thr 755 760 765Leu Glu Glu Glu Glu
Ile Ala Ala Thr Val Ala Lys Cys Val Glu Ala 770 775 780Leu Lys Glu
Arg Phe Gln Ala Ser Leu Arg Asp785 790 79553785PRTThermus
thermophilus 53Met Arg Val Pro Phe Ser Trp Leu Lys Ala Tyr Val Pro
Glu Leu Glu1 5 10 15Ser Pro Glu Val Leu Glu Glu Arg Leu Ala Gly Leu
Gly Phe Glu Thr 20 25 30Asp Arg Ile Glu Arg Val Phe Pro Ile Pro Arg
Gly Val Val Phe Ala 35 40 45Arg Val Leu Glu Ala His Pro Ile Pro Gly
Thr Arg Leu Lys Arg Leu 50 55 60Val Leu Asp Ala Gly Arg Thr Val Glu
Val Val Ser Gly Ala Glu Asn65 70 75 80Ala Arg Lys Gly Ile Gly Val
Ala Leu Ala Leu Pro Gly Thr Glu Leu 85 90 95Pro Gly Leu Gly Gln Lys
Val Gly Glu Arg Val Ile Gln Gly Val Arg 100 105 110Ser Phe Gly Met
Ala Leu Ser Pro Arg Glu Leu Gly Val Gly Glu Tyr 115 120 125Gly Gly
Gly Leu Leu Glu Phe Pro Glu Asp Ala Leu Pro Pro Gly Thr 130 135
140Pro Leu Ser Glu Ala Trp Pro Glu Glu Val Val Leu Asp Leu Glu
Val145 150 155 160Thr Pro Asn Arg Pro Asp Ala Leu Gly Leu Leu Gly
Leu Ala Arg Asp 165 170 175Leu His Ala Leu Gly Tyr Ala Leu Val Glu
Pro Glu Ala Ala Leu Lys 180 185 190Ala Glu Ala Leu Pro Leu Pro Phe
Ala Leu Lys Val Glu Asp Pro Glu 195 200 205Gly Ala Pro His Phe Thr
Leu Gly Tyr Ala Phe Gly Leu Arg Val Ala 210 215 220Pro Ser Pro Leu
Trp Met Gln Arg Ala Leu Phe Ala Ala Gly Met Arg225 230 235 240Pro
Ile Asn Asn Val Val Asp Val Thr Asn Tyr Val Met Leu Glu Arg 245 250
255Ala Gln Pro Met His Ala Phe Asp Leu Arg Phe Val Gly Glu Gly Ile
260 265 270Ala Val Arg Arg Ala Arg Glu Gly Glu Arg Leu Lys Thr Leu
Asp Gly 275 280 285Val Glu Arg Thr Leu His Pro Glu Asp Leu Val Ile
Ala Gly Trp Arg 290 295 300Gly Glu Glu Ser Phe Pro Leu Gly Leu Ala
Gly Val Met Gly Gly Ala305 310 315 320Glu Ser Glu Val Arg Glu Asp
Thr Glu Ala Ile Ala Leu Glu Val Ala 325 330 335Cys Phe Asp Pro Val
Ser Ile Arg Lys Thr Ala Arg Arg His Gly Leu 340 345 350Arg Thr Glu
Ala Ser His Arg Phe Glu Arg Gly Val Asp Pro Leu Gly 355 360 365Gln
Val Pro Ala Gln Arg Arg Ala Leu Ser Leu Leu Gln Ala Leu Ala 370 375
380Gly Ala Arg Val Ala Glu Ala Leu Leu Glu Ala Gly Ser Pro Lys
Pro385 390 395 400Pro Glu Ala Ile Pro Phe Arg Pro Glu Tyr Ala Asn
Arg Leu Leu Gly 405 410 415Thr Ser Tyr Pro Glu Ala Glu Gln Ile Ala
Ile Leu Lys Arg Leu Gly 420 425 430Cys Arg Val Glu Gly Glu Gly Pro
Thr Tyr Arg Val Thr Pro Pro Ser 435 440 445His Arg Leu Asp Leu Arg
Leu Glu Glu Asp Leu Val Glu Glu Val Ala 450 455 460Arg Ile Gln Gly
Tyr Glu Thr Ile Pro Leu Ala Leu Pro Ala Phe Phe465 470 475 480Pro
Ala Pro Asp Asn Arg Gly Val Glu Ala Pro Tyr Arg Lys Glu Gln 485 490
495Arg Leu Arg Glu Val Leu Ser Gly Leu Gly Phe Gln Glu Val Tyr Thr
500 505 510Tyr Ser Phe Met Asp Pro Glu Asp Ala Arg Arg Phe Arg Leu
Asp Pro 515 520 525Pro Arg Leu Leu Leu Leu Asn Pro Leu Ala Pro Glu
Lys Ala Ala Leu 530 535 540Arg Thr His Leu Phe Pro Gly Leu Val Arg
Val Leu Lys Glu Asn Leu545 550 555 560Asp Leu Asp Arg Pro Glu Arg
Ala Leu Leu Phe Glu Val Gly Arg Val 565 570 575Phe Arg Glu Arg Glu
Glu Thr His Leu Ala Gly Leu Leu Phe Gly Glu 580 585 590Gly Val Gly
Leu Pro Trp Ala Lys Glu Arg Leu Ser Gly Tyr Phe Leu 595 600 605Leu
Lys Gly Tyr Leu Glu Ala Leu Phe Ala Arg Leu Gly Leu Ala Phe 610 615
620Arg Val Glu Ala Gln Ala Phe Pro Phe Leu His Pro Gly Val Ser
Gly625 630 635 640Arg Val Leu Val Glu Gly Glu Glu Val Gly Phe Leu
Gly Ala Leu His 645 650 655Pro Glu Ile Ala Gln Glu Leu Glu Leu Pro
Pro Val His Leu Phe Glu 660 665 670Leu Arg Leu Pro Leu Pro Asp Lys
Pro Leu Ala Phe Gln Asp Pro Ser 675 680 685Arg His Pro Ala Ala Phe
Arg Asp Leu Ala Val Val Val Pro Ala Pro 690 695 700Thr Pro Tyr Gly
Glu Val Glu Ala Leu Val Arg Glu Ala Ala Gly Pro705 710 715 720Tyr
Leu Glu Ser Leu Ala Leu Phe Asp Leu Tyr Gln Gly Pro Pro Leu 725 730
735Pro Glu Gly His Lys Ser Leu Ala Phe His Leu Arg Phe Arg His Pro
740 745 750Lys Arg Thr Leu Arg Asp Glu Glu Val Glu Glu Ala Val Ser
Arg Val 755 760 765Ala Glu Ala Leu Arg Ala Arg Gly Phe Gly Leu Arg
Gly Leu Asp Thr 770 775 780Pro78554556PRTPyrococcus horikoshii
54Met Pro Lys Phe Asp Val Ser Lys Ser Asp Leu Glu Arg Leu Ile Gly1
5 10 15Arg Ser Phe Ser Ile Glu Glu Trp Glu Asp Leu Val Leu Tyr Ala
Lys 20 25 30Cys Glu Leu Asp Asp Val Trp Glu Glu Asn Gly Lys Val Tyr
Phe Lys 35 40 45Leu Asp Ser Lys Asp Thr Asn Arg Pro Asp Leu Trp Ser
Ala Glu Gly 50 55 60Val Ala Arg Gln Ile Lys Trp Ala Leu Gly Ile Glu
Lys Gly Leu Pro65 70 75 80Lys Tyr Glu Val Lys Lys Ser Asn Val Thr
Val Tyr Val Asp Glu Lys 85 90 95Leu Lys Asp Ile Arg Pro Tyr Gly Val
Tyr Ala Ile Val Glu Gly Leu 100 105 110Arg Leu Asp Glu Asp Ser Leu
Ser Gln Met Ile Gln Leu Gln Glu Lys 115 120 125Ile Ala Leu Thr Phe
Gly Arg Arg Arg Arg Glu Val Ala Ile Gly Ile 130 135 140Phe Asp Phe
Asp Lys Ile Lys Pro Pro Ile Tyr Tyr Lys Ala Ala Glu145 150 155
160Lys Thr Glu Lys Phe Ala Pro Leu Gly Tyr Lys Glu Glu Met Thr Leu
165 170 175Glu Glu Ile Leu Glu Lys His Glu Lys Gly Arg Glu Tyr Gly
His Leu 180 185 190Ile Lys Asp Lys Gln Phe Tyr Pro Leu Leu Ile Asp
Ser Glu Gly Asn 195 200 205Val Leu Ser Met Pro Pro Ile Ile Asn Ser
Glu Phe Thr Gly Arg Val 210 215 220Thr Thr Asp Thr Lys Asn Val Phe
Ile Asp Val Thr Gly Trp Lys Leu225 230 235 240Glu Lys Val Met Leu
Ala Leu Asn Val Met Val Thr Ala Leu Ala Glu 245 250 255Arg Gly Gly
Lys Ile Arg Ser Val Arg Val Val Tyr Lys Asp Phe Glu 260 265 270Ile
Glu Thr Pro Asp Leu Thr Pro Lys Glu Phe Glu Val Glu Leu Asp 275 280
285Tyr Ile Arg Lys Leu Ser Gly Leu Glu Leu Asn Asp Gly Glu Ile Lys
290 295 300Glu Leu Leu Glu Lys Met Met Tyr Glu Val Glu Ile Ser Arg
Gly Arg305 310 315 320Ala Lys Leu Lys Tyr Pro Ala Phe Arg Asp Asp
Ile Met His Ala Arg 325 330 335Asp Ile Leu Glu Asp Val Leu Ile Ala
Tyr Gly Tyr Asn Asn Ile Glu 340 345 350Pro Glu Glu Pro Lys Leu Ala
Val Gln Gly Arg Gly Asp Pro Phe Lys 355 360 365Asp Phe Glu Asp Ala
Ile Arg Asp Leu Met Val Gly Phe Gly Leu Gln 370 375 380Glu Val Met
Thr Phe Asn Leu Thr Asn Lys Glu Val Gln Phe Lys Lys385 390 395
400Met Asn Ile Pro Glu Glu Glu Ile Val Glu Ile Ala Asn Pro Ile Ser
405 410 415Gln Arg Trp Ser Ala Leu Arg Lys Trp Ile Leu Pro Ser Leu
Met Glu 420 425 430Phe Leu Ser Asn Asn Thr His Glu Glu Tyr Pro Gln
Arg Ile Phe Glu 435 440 445Val Gly Leu Ala Thr Leu Ile Asp Glu Ser
Arg Glu Thr Lys Thr Val 450 455 460Ser Glu Pro Lys Leu Ala Val Ala
Leu Ala Gly Thr Gly Tyr Thr Phe465 470 475 480Thr Asn Ala Lys Glu
Ile Leu Asp Ala Leu Met Arg His Leu Gly Phe 485 490 495Glu Tyr Glu
Ile Glu Glu Val Glu His Gly Ser Phe Ile Pro Gly Arg 500 505 510Ala
Gly Lys Ile Ile Val Asn Gly Arg Asp Ile Gly Ile Ile Gly Glu 515 520
525Val His Pro Gln Val Leu Glu Asn Trp Asn Ile Glu Val Pro Val Val
530 535 540Ala Phe Glu Ile Phe Leu Arg Pro Leu Tyr Arg His545 550
5555534DNAArtificial SequenceDescription of Artificial
SequencePrimer Ec-B1-F 55gcaccgcata tgaaattcag tgaactgtgg ttac
345634DNAArtificial SequenceDescription of Artificial
SequencePrimer Ec-B5-R 56gtgcctcgag cgggatgttg ttgtagccgt aaac
345743DNAArtificial SequenceDescription of Artificial
SequencePrimer Ec-B3/4-R 57gtgcctcgag acgcttcggc agcgttgctt
cgttggtgat atc 435834DNAArtificial SequenceDescription of
Artificial SequencePrimer Ec-B3/4-F 58gcacgccata tggttcaacc
ggaaatcgtt ccgg 345937DNAArtificial SequenceDescription of
Artificial SequencePrimer Tt-B1-F 59gccgcccata tgagggtgcc
cttctcctgg ctaaaag 376037DNAArtificial SequenceDescription of
Artificial
SequencePrimer Tt-B5-R 60gctcgaagct tggggatggt ctcgtagccc tggatgc
376144DNAArtificial SequenceDescription of Artificial
SequencePrimer Tt-B3/4-R 61gctcgaagct tcgggggctt ggggcttccc
gcctcgagga gggc 446237DNAArtificial SequenceDescription of
Artificial SequencePrimer Tt-B3/4-F 62gccgcccata tggccctgaa
ggcggaggcc cttcccc 376335DNAArtificial SequenceDescription of
Artificial SequencePrimer Ph-B1-F 63ggcgcgccca tatgccaaag
ttcgacgttt caaag 356429DNAArtificial SequenceDescription of
Artificial SequencePrimer Ph-B5-R 64agctcgaggg gctctatgtt attatatcc
296530DNAArtificial SequenceDescription of Artificial
SequencePrimer Ph-B3/4-R 65ggctcgagta aatctggggt ttcaatttcg
306637DNAArtificial SequenceDescription of Artificial
SequencePrimer Ph-B3/4-F 66gccggcccca tatggaggtt aaaaagagta acgtaac
376735DNAArtificial SequenceDescription of Artificial
SequencePrimer Ec-Mu-F 67ggcctgcata ccgattggtc tcaccgttat gagcg
356835DNAArtificial SequenceDescription of Artificial
SequencePrimer Ec-Mu-R 68cgctcataac ggtgagacca atcggtatgc aggcc
356933DNAArtificial SequenceDescription of Artificial
SequenceTt-Mu-F 69ggcctgcgca ccgagtggag ccaccgcttt gag
337033DNAArtificial SequenceDescription of Artificial
SequenceTt-Mu-R 70ctcaaagcgg tggctccact cggtgcgcag gcc
337130DNAArtificial SequenceDescription of Artificial
SequencePrimer Ph-Mu-F 71gaaggagaga agtgtggata ggaatcttcg
307230DNAArtificial SequenceDescription of Artificial
SequencePrimer Ph-Mu-R 72cgaagattcc tatccacact tctctccttc
307317DNAArtificial SequenceDescription of Artificial SequenceT7
promoter 73taatacgact cactata 17
* * * * *