U.S. patent application number 10/890179 was filed with the patent office on 2004-12-30 for recombinant expression of s-layer proteins.
This patent application is currently assigned to Lubitz, Prof. Werner. Invention is credited to Howorka, Stefan, Kuen, Beatrix, Lubitz, Werner, Resch, Stepanka, Sara, Margit, Schroll, Gerhard, Sleytr, Uwe, Truppe, Michaela.
Application Number | 20040265936 10/890179 |
Document ID | / |
Family ID | 7784274 |
Filed Date | 2004-12-30 |
United States Patent
Application |
20040265936 |
Kind Code |
A1 |
Lubitz, Werner ; et
al. |
December 30, 2004 |
Recombinant expression of S-layer proteins
Abstract
The invention concerns a process for the recombinant production
of S-layer proteins in gram-negative host cells. Furthermore the
nucleotide sequence of a new S-layer gene and processes for the
production of modified S-layer proteins are disclosed.
Inventors: |
Lubitz, Werner; (Vienna,
AT) ; Sleytr, Uwe; (Vienna, AT) ; Kuen,
Beatrix; (Vienna, AT) ; Truppe, Michaela;
(Luftenberg, AT) ; Howorka, Stefan; (Vienna,
AT) ; Resch, Stepanka; (Vienna, AT) ; Schroll,
Gerhard; (Vienna, AT) ; Sara, Margit;
(Gaenserndorf, AT) |
Correspondence
Address: |
ROTHWELL, FIGG, ERNST & MANBECK, P.C.
1425 K STREET, N.W.
SUITE 800
WASHINGTON
DC
20005
US
|
Assignee: |
Lubitz, Prof. Werner
NANO-S Biotechnologie GmbH
Vienna
AT
Vienna
AT
|
Family ID: |
7784274 |
Appl. No.: |
10/890179 |
Filed: |
July 14, 2004 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
10890179 |
Jul 14, 2004 |
|
|
|
09117447 |
Dec 2, 1998 |
|
|
|
6777202 |
|
|
|
|
09117447 |
Dec 2, 1998 |
|
|
|
PCT/EP97/00432 |
Jan 31, 1997 |
|
|
|
Current U.S.
Class: |
435/7.32 ;
435/252.3; 435/320.1; 435/69.3; 530/395; 536/23.7 |
Current CPC
Class: |
C12N 9/1029 20130101;
C07K 2319/40 20130101; A61P 31/04 20180101; A61P 31/00 20180101;
A61K 39/00 20130101; C07K 2319/02 20130101; C12N 2710/16722
20130101; C07K 14/32 20130101; C07K 14/415 20130101; C07K 14/005
20130101; C07K 2319/735 20130101; C12N 15/62 20130101 |
Class at
Publication: |
435/007.32 ;
435/069.3; 435/320.1; 435/252.3; 530/395; 536/023.7 |
International
Class: |
G01N 033/554; G01N
033/569; C07H 021/04; C12N 001/21; C07K 014/32 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 1, 1996 |
DE |
196 03 649.6 |
Claims
1. A recombinant S-layer protein, wherein said protein is coded by
an isolated nucleic acid selected from the group consisting of (i)
a nucleic acid comprising a nucleotide sequence from position 1 to
3684 of SEQ ID NO:1, (ii) a nucleic acid comprising a nucleotide
sequence which encodes an amino acid sequence according to SEQ ID
NO:2, and (iii) a nucleic acid comprising a nucleotide sequence
which hybridizes with at least one of the nucleic acids of (i) or
(ii) under stringent conditions, wherein the nucleic acid contains
at least one peptide or polypeptide-coding insertion within the
region coding for the S-layer protein.
2. The protein according to claim 1, wherein the insertion site is
located at position 582, 878, 917, 2504 and/or 2649 of the
nucleotide sequence shown in SEQ ID NO:1.
3. A recombinant S-layer structure, wherein said structure contains
at least one protein according to claim 1 as a subunit.
4. The S-layer structure as claimed in claim 3, further comprising
at least one unmodified S-layer protein as a subunit.
5. The S-layer structure as claimed in claim 3, wherein it
comprises several layers which are linked covalently or by affinity
binding.
6. The recombinant S-layer protein as claimed in claim 1, wherein
the insertions code for streptavidin.
7. The recombinant S-layer protein as claimed in claim 1, wherein
the insertions code for immunogenic epitopes from herpes viruses,
in particular herpes virus 6 or FMDV.
8. The recombinant S-layer protein as claimed in claim 1, wherein
the insertions code for enzymes such as polyhydroxybutyric acid
synthase or bacterial luciferase.
9. The recombinant S-layer protein as claimed in claim 1, wherein
the insertions code for cytokines such as interleukins, interferons
or tumour necrosis factors.
10. The recombinant S-layer protein as claimed in claim 1, wherein
the insertions code for antibody-binding proteins such as protein A
or protein G.
11. The recombinant S-layer protein as claimed in claim 1, wherein
the insertions code for antigenic epitopes which bind cytokines or
endotoxins.
12. The recombinant S-layer protein as claimed in claim 1, wherein
the insertions code for metal-binding epitopes.
13. The recombinant S-layer protein as claimed in claim 1, wherein
the insertions are selected from nucleotide sequences which code
for cysteine residues, regions with several charged amino acids or
Tyr residues, DNA-binding epitopes, metal binding epitopes,
immunogenic epitopes, allergenic epitopes, antigenic epitopes,
streptavidin, enzymes, cytokines or antibody-binding proteins.
14. An S-layer protein, wherein said protein is coded by a nucleic
acid selected from the group consisting of: (i) a nucleic acid
comprising a nucleotide sequence from position 1 to 2763 of SEQ ID
NO:5, (ii) a nucleic acid comprising a nucleotide sequence
corresponding to the nucleic acid from (i) within the scope of the
degeneracy of the genetic code, and (iii) a nucleic acid comprising
a nucleotide sequence which hybridizes with at least one of the
nucleic acids of (i) or (ii) under stringent conditions, wherein
the nucleic acid contains at least one peptide or
polypeptide-coding insertion within the region encoding the S-layer
protein.
15. A recombinant S-layer structure, wherein said structure
contains at least one recombinant S-layer protein according to
claim 14 as a subunit.
16. The recombinant S-layer protein as claimed in claim 14, wherein
the insertions are selected from nucleotide sequences which code
for cysteine residues, regions with several charged amino acids or
Tyr residues, DNA-binding epitopes, metal-binding epitopes,
immunogenic epitopes, allergenic epitopes, antigenic epitopes,
streptavidin, enzymes, cytokines or antibody-binding proteins.
17. The recombinant S-layer protein as claimed in claim 14, wherein
the insertions code for streptavidin.
18. The recombinant S-layer protein as claimed in claim 14, wherein
the insertions code for immunogenic epitopes from herpes viruses,
in particular herpes virus 6 or FMDV.
19. The recombinant S-layer protein as claimed in claim 14, wherein
the insertions code for enzymes such as polyhydroxybutyric acid
synthase or bacterial luciferase.
20. The recombinant S-layer protein as claimed in claim 14, wherein
the insertions code for cytokines such as interleukins, interferons
or tumour necrosis factors.
21. The recombinant S-layer protein as claimed in claim 14, wherein
the insertions code for antibody-binding proteins such as protein A
or protein G.
22. The recombinant S-layer protein as claimed in claim 14, wherein
the insertions code for antigenic epitopes which bind cytokines or
endotoxins.
23. The recombinant S-layer protein as claimed in claim 14, wherein
the insertions code for metal-binding epitopes.
Description
[0001] The present invention concerns processes for the recombinant
production of S-layer proteins and modified S-layer proteins in
gram-negative host cells.
[0002] Crystalline bacterial cell surface layers (S-layers) form
the outermost cell wall component in many eubacteria and most of
the archaebacteria (Sleytr et al. (1988), Crystalline Bacterial
Cell Surface Layers, "Springer Verlag Berlin"; Messner and Sleytr,
Adv. Microb. Physiol. 33 (1992), 213-275). Most of the presently
known S-layer proteins are composed of identical proteins or
glycoproteins which have apparent molecular weights in the range of
40,000 to 220,000. The components of S-layers are self-assembling
and most of the lattices have an oblique (p2), quadratic (p4) or
hexagonal (p6) symmetry. The functions of bacterial S-layers are
still not completely understood but due to their location on the
cell surface the porous crystalline S-layers probably serve mainly
as protective coatings, molecular sieves or to promote cell
adhesion and surface recognition.
[0003] Genetic data and sequence information are known for various
S-layer genes from microorganisms. A review may be found in Peyret
et al., Mol. Microbiol. 9 (1993), 97-109. Explicit reference is
made to these data. The sequence of the sbsA gene coding for the
S-layer protein of B.stearothermophilus PV72 and a process for
cloning it are stated in Kuen et al. (Gene 145 (1994), 115-120).
B.stearothermophilus PV72 is a gram-positive bacterium which is
covered with a hexagonally arranged S-layer. The main component of
the S-layer is a 128 kd protein which is the most frequent protein
in the cell with a proportion of about 15% relative to the total
protein components. Various strains of B.stearothermophilus have
been characterized which differ with regard to the type of the
S-layer lattice, the molecular weight and glycosilation of the
S-layer components (Messner and Sleytr (1992), supra).
[0004] The German Patent Application P 44 25 527.6 discloses the
signal peptide-coding section of the S-layer gene from
B.stearothermophilus and the amino acid sequence derived therefrom.
The cleavage site between the signal peptide and the mature protein
is located between position 30 and 31 of the amino acid sequence.
The signal peptide-coding nucleic acid can be operatively linked to
a protein-coding nucleic acid and can be used for the recombinant
production of proteins in a process in which a transformed host
cell is provided, the host cell is cultured under conditions which
lead to an expression of the nucleic acid and to production and
secretion of the polypeptide coded thereby and the resulting
polypeptide is isolated from the culture medium. Prokaryotic
organisms are preferably used as host cells in particular
gram-positive organisms of the genus bacillus.
[0005] Surprisingly it was found that the recombinant production of
S-layer proteins is not only possible in gram-positive prokaryotic
host cells but also in gram-negative prokaryotic host cells. In
this case the S-layer protein is not formed in the interior of the
host cell in the form of ordered inclusion bodies but rather
unexpectedly in the form of ordered monomolecular layers.
[0006] Hence one subject matter of the present invention is a
process for the recombinant production of S-layer proteins
characterized in that (a) a gram-negative prokaryotic host cell is
provided which is transformed with a nucleic acid coding for an
S-layer protein selected from (i) a nucleic acid which comprises
the nucleotide sequence shown in SEQ ID NO. 1 from position 1 to
3684 optionally without the section coding for the signal peptide,
(ii) a nucleic acid which comprises a nucleotide sequence
corresponding to the nucleic acid from (i) within the scope of the
degeneracy of the genetic code and (iii) a nucleic acid which
comprises a nucleotide sequence which hybridizes with the nucleic
acids from (i) or/and (ii) under stringent conditions; (b) the host
cell is cultured under conditions which lead to an expression of
the nucleic acid and to production of the polypeptide coded thereby
and (c) the resulting polypeptide is isolated from the host
cell.
[0007] The term "stringent hybridization" is understood within the
sense of the present invention to mean that a hybridization still
also occurs after washing at 55.degree. C., preferably 60.degree.
C. in an aqueous low salt buffer (e.g. 0.2.times.SSC) (see also
Sambrook et al. (1989), Molecular Cloning. A Laboratory
Manual).
[0008] The process according to the invention is carried out in
gram-negative prokaryotic host cells. In this process an ordered
S-layer protein structure is surprisingly obtained in the cell
interior. Enterobacteria, in particular E. coli, are preferably
used as host cells.
[0009] The E. coli strain pop2125 which was deposited on the
31.01.1996 at the "Deutsche Sammlung von Mikroorganismen und
Zellkulturen GmbH", Mascheroder Weg 1b, D 38124 Braunschweig under
the file number DSM 10509 is particularly preferred.
[0010] The process according to the invention can also be used to
isolate recombinant S-layer proteins. For this one uses a nucleic
acid coding for the S-layer protein which contains one or several
insertions which code for peptide or polypeptide sequences. These
insertions can, on the one hand, only code for peptides with a few
amino acids e.g. 1-25 amino acids. On the other hand, the
insertions can also code for larger polypeptides of for example up
to 1000 amino acids and preferably up to 500 amino acids without
loss of the ability of the S-layer protein to form a correctly
folded structure. In addition to the insertions the recombinant
S-layer protein can also have amino acid substitutions, in
particular substitutions of individual amino acids in the region of
the insertion sites as well as optionally deletions of individual
amino acids or short amino acid sections of up to 30 amino
acids.
[0011] Regions between the positions 1-1200 and 2200-3000 of the
nucleotide sequence shown in SEQ ID NO.1 are preferred as insertion
sites for polypeptide-coding sequences. Particularly preferred
insertion sites are the NruI cleavage site at position 582, the
PvuII cleavage site at position 878, the SnaB-I cleavage site at
position 917, the PVuII cleavage site at position 2504 and the
PvuII cleavage site at position 2649. It was already possible to
demonstrate the insertion of a nucleic acid coding for streptavidin
into the NruI cleavage site at position 581.
[0012] The peptide or polypeptide-coding insertions are preferably
selected from nucleotide sequences which code for cysteine
residues, regions with several charged amino acids, e.g. Arg, Lys,
Asp or Glu, or Tyr residues, DNA-binding epitopes, antigenic,
allergenic or immunogenic epitopes, metal-binding epitopes,
streptavidin, enzymes, cytokines or antibody-binding proteins.
[0013] A particularly preferred example of an insertion into the
nucleic acid coding for the S-layer protein is a nucleotide
sequence coding for streptavidin. In this manner it is possible to
obtain universal carrier molecules which are suitable for coupling
biotinylated reagents and for detection in immunological or
hybridization test procedures.
[0014] A further preferred example of insertions are antigenic,
allergenic or immunogenic epitopes e.g. epitopes from pathogenic
microorganisms such as bacteria, fungi, parasites etc. and viruses,
or epitopes from plants or epitopes against endogenous substances
e.g. cytokines as well as against toxins in particular endotoxins.
Particularly preferred examples of immunogenic epitopes are
epitopes from herpes viruses such as the herpes virus 6 or
pseudorabies virus (Lomniczi et al., J. Virol. 49 (1984), 970-979),
in particular epitopes from the genes gB, gC or/and gD, or
foot-and-mouth disease virus (FMDV), in particular epitopes from
the gene sections which code for VP1, VP2 or/and VP3. The
immunogenic epitopes can be selected such that they promote an
antibody-mediated immune reaction or/and the production of a
cellular immune reaction e.g. by stimulation of T cells. Examples
of suitable allergenic epitopes are birch pollen allergens e.g. Bet
v I (Ebner et al., J. Immunol. 150 (1993) 1047-1054). Antigenic
epitopes are additionally particularly preferred which are able to
bind and filter out endogenous or exogenous substances such as
cytokines or toxins from serum or other body fluids. Such epitopes
can include components of cytokine or toxin receptors or of
antibodies against cytokines or toxins.
[0015] On the other hand the insertions can also code for enzymes.
Preferred examples are enzymes for the synthesis of
polyhydroxybutyric acid e.g. PHB synthase. Incorporation of PHB
synthase into the S-layer can lead to the formation of a molecular
spinning nozzle under suitable conditions when the substrate
hydroxybutyric acid is provided. A further preferred example of an
enzyme is bacterial luciferase. In this case when the enzyme
substrate, an aldehyde, is supplied and O.sub.2 is present, a
molecular laser can be obtained.
[0016] Insertions are likewise preferred which code for cytokines
such as interleukins, interferones or tumour necrosis factors.
These molecules can for example be used in combination with
immunogenic epitopes to prepare vaccines.
[0017] Finally insertions are also preferred which code for
antibody binding proteins such as protein A or protein G or for
DNA-binding or/and metal-binding epitopes such as the leucine
zipper, zinc finger etc.
[0018] Thus for the first time a cell is provided by the present
invention which contains immobilized recombinant polypeptides in a
native form e.g. active enzymes in the cytoplasm. In this manner
50,000-200,000 e.g. ca. 100,000 recombinant molecules can be
immobilized per m.sup.2 recombinant S-layer. Up to 3000 m.sup.2
S-layer can be obtained per kg recombinant E. coli cells.
[0019] In the method according to the invention the nucleic acid
coding for the S-layer protein is preferably used in operative
linkage with a nucleic acid coding for a signal peptide of
gram-positive bacteria i.e. the signal peptide-coding nucleic acid
is located on the 5' side of the S-layer protein-coding nucleic
acid. Surprisingly it was found that the presence of such signal
peptide sequences, which are not cleaved in the gram-negative host
cells used in the invention, can improve the stability of the
S-layer structures. The nucleic acid coding for the signal peptide
particularly preferably comprises (a) the signal peptide-coding
section of the nucleotide sequence shown in SEQ ID NO. 1, (b) a
nucleotide sequence corresponding to the sequence from (a) within
the scope of the degeneracy of the genetic code or/and (c) a
nucleotide sequence which is at least 80% and in particular at
least 90% homologous to the sequences from (a) or/and (b).
[0020] Yet a further subject matter of the present invention is a
nucleic acid which codes for a recombinant S-layer protein and is
selected from (i) a nucleic acid which comprises the nucleotide
sequence shown in SEQ ID NO.1 from position 1 to 3684 optionally
without the signal peptide-coding-section (ii) a nucleic acid which
comprises a nucleotide sequence corresponding to a nucleic acid
from (i) within the scope of the degeneracy of the genetic code and
(iii) a nucleic acid which comprises a nucleotide sequence which
hybridizes under stringent conditions with the nucleic acids from
(i) or/and (ii).
[0021] The coding nucleotide sequence of the S-layer gene sbsA from
B.stearothermophilus including the signal peptide-coding section is
shown in SEQ ID NO. 1. The signal peptide-coding section extends
from position 1 to 90 of the nucleotide sequence shown in SEQ ID
NO. 1. The section coding for the mature SbsA polypeptide extends
from position 91 to 3684.
[0022] The sbsA gene of B.stearothermophilus codes for a protein
with a total of 1228 amino acids including an N-terminal signal
peptide with 30 amino acids (SEQ ID NO. 2). The cleavage site
between the signal peptide and the mature protein is located
between position 30 and 31 of the amino acid sequence. The signal
peptide has a basic amino-terminal domain followed by a hydrophobic
domain.
[0023] Sequence comparisons with other signal peptides indicate a
certain homology to signal peptides of extracellular proteins in
bacilli such as alkaline phosphatase and neutral phosphatase of
B.amyloliquefaciens (Vasantha et al., J. Bacteriol. 159 (1984),
811-819) as well as with the signal peptides for the B.sphaericus
gene 125 (Bowditch et al., J. Bacteriol. 171 (1989), 4178-4188) and
the OWP gene of B.brevis (Tsuboi et al., J. Bacteriol. 168 (1986),
365-373).
[0024] A further subject matter of the present invention is a
recombinant vector which contains at least one copy of a nucleic
acid according to the invention. The vector is preferably
replicatable in prokaryotes. The vector is particularly preferably
a prokaryotic plasmid.
[0025] Yet a further subject matter of the present invention is a
host cell which is transformed with a nucleic acid or a recombinant
vector according to the present invention. The cell is preferably a
gram-negative prokaryotic organism and most preferably an E. coli
cell. The cell according to the invention can contain a recombinant
S-layer structure in its interior. Methods for the transformation
of cells with nucleic acids are general state of the art (cf.
Sambrook et al., supra) and therefore do not need to be
elucidated.
[0026] Yet a further subject matter of the present invention is a
recombinant S-layer protein which contains at least one peptide
insertion or/and polypeptide insertion within the amino acid
sequence shown in SEQ ID NO. 2. Preferred examples of peptide
insertions and polypeptide insertions have already been
elucidated.
[0027] A recombinant S-layer structure can be assembled from
recombinant S-layer protein molecules according to the invention
which contain at least one recombinant S-layer protein according to
the invention as a subunit. Furthermore it is preferred that the
S-layer structure according to the invention also contains
non-modified S-layer proteins as diluent molecules. The
non-modified S-layer proteins are preferably present in a molar
proportion of 10-99% relative to the total S-layer proteins.
[0028] The S-layer structure according to the invention can
comprise several layers that are covalently linked together or by
means of affinity binding. Covalent linkages can for example be
introduced by insertions of cysteine residues and a subsequent
formation of cystine bridges. Linkages by affinity binding comprise
for example antibody-antigen, antibody-protein A or
antibody-protein G or streptavidin-biotin interactions.
[0029] S-layer structures which contain recombinant S-layer
proteins can optionally also be prepared in a carrier-bound form.
For this the S-layer structure can be reassembled from individual
units in the presence of a peptidoglycan carrier to for example
produce peptidoglycan layers which are covered on one or on both
sides with an S-layer structure. Another method of preparing
carrier-bound S-layer structures is to produce an S-layer layer at
an interface between two media e.g. water/air and to immobilize
this layer on a solid phase e.g. a filter membrane (cf. e.g. Pum
and Sleytr (1994), Thin Solid Films 244, 882-886; Kupcu et al.,
(1995), Biochim. Biophys. Acta 1235, 263-269).
[0030] The recombinant S-layer proteins and S-layer structures
according to the invention are suitable for a multitude of
applications. An application as a vaccine or adjuvant is
particularly preferred in which case recombinant S-layer proteins
are used which contain immunogenic epitopes of pathogens and/or
endogenous immunostimulatory polypeptides such as cytokines. In
this application it is not absolutely necessary to purify the
recombinant S-layer proteins. Instead they can for example be used
in combination with a bacterial ghost which optionally contains
additional immunogenic epitopes in its membrane.
[0031] The preparation of suitable "bacterial ghosts" is described
for example in the International Patent application PCT/EP91/00967
to which reference is herewith made. In this application modified
bacteria are disclosed which are obtainable by transformation of a
gram-negative bacterium with the gene of a lytically active
membrane protein from bacteriophages, with the gene of a lytically
active toxin release protein or with genes which contain partial
sequences thereof which code for lytic proteins, culturing the
bacterium, expression of this lysis gene and isolation of the
resulting bacterial ghost from the culture medium.
[0032] A recombinant protein, which is obtainable by expression of
a recombinant DNA in these gram-negative bacteria, can be bound to
the membrane of these bacteria as described in the European Patent
0 516 655. This recombinant DNA comprises a first DNA sequence
which codes for a hydrophobic, non-lytically active
membrane-integrating protein domain which has an .alpha.-helical
structure and is composed of 14-20 amino acids which can be flanked
N- and C-terminally by 2-30 arbitrary amino acids in each case. A
second DNA sequence is in operative linkage with this first DNA
sequence which codes for a desired recombinant protein. Furthermore
the gram-negative bacterium contains a third DNA sequence which is
under a different control from the first and second DNA sequences
and codes for a lytically active membrane protein from
bacteriophages or a lytically active toxin release protein or for
their lytically active components. So-called "bacterial ghosts" are
obtained by expression and lysis of such recombinant gram-negative
bacteria which contain an intact surface structure with immunogenic
epitopes bound to the surface.
[0033] When these bacterial ghosts are combined with recombinant
S-layers according to the invention vaccines and adjuvants can be
produced which have particularly advantageous properties.
[0034] A further particularly preferred application for recombinant
S-layer proteins and S-layer structures is their use as an enzyme
reactor. Such an enzyme reactor can for example be formed by a cell
which contains a recombinant S-layer structure according to the
invention in its interior. On the other hand the enzyme reactor can
also be formed from isolated and in vitro reassembled S-layer
structures or combinations of various S-layer structures.
[0035] It was found that the gram-positive bacterium
B.stearothermophilus PV72 has an additional S-layer protein in
addition to SbsA which is subsequently denoted as SbsB (Sara and
Sleytr (1994), J. Bacteriol. 176, 7182-7189). It was possible to
isolate and characterize the sbsB gene by amplification using
suitable nucleic acid primers. The coding nucleotide sequence of
the S-layer gene sbsB from B.stearothermophilus including the
signal peptide-coding section which extends from position 1 to 93
of the nucleic acid sequence is shown in SEQ ID NO.5. The amino
acid sequence derived therefrom is shown in SEQ ID NO.6. The sbsB
gene codes for a protein with a total of 921 amino acids including
an N-terminal signal peptide with 31 amino acids.
[0036] One subject matter of the present invention is hence a
nucleic acid which codes for an S-layer protein and is selected
from
[0037] (i) a nucleic acid which comprises the nucleotide sequence
from position 1 to 2763 shown in SEQ ID NO.5 optionally without the
signal peptide-coding section,
[0038] (ii) a nucleic acid which comprises a nucleotide sequence
corresponding to the nucleic acid from (i) within the scope of the
degeneracy of the genetic code and
[0039] (iii) a nucleic acid which comprises a nucleotide sequence
that hybridizes with the nucleic acids from (i) or/and (ii) under
stringent conditions.
[0040] As in the case of the sbsA-gene, it is also possible to
insert at least one nucleic acid insertion coding for a peptide or
polypeptide into the sbsB gene within the region coding for the
S-layer protein. With regard to preferred examples of insertions in
the sbsB gene reference is made to the previous statements
regarding the sbsA gene.
[0041] Yet a further subject matter of the present invention is a
vector which contains at least one copy of an sbsB gene optionally
containing an insertion. This vector can be replicated in
eukaryotes, prokaryotes or in eukaryotes and prokaryotes. It can be
a vector that can be integrated into the genome of the host cell or
a vector which is present extrachromosomally. The vector according
to the invention is preferably a plasmid in particular a
prokaryotic plasmid.
[0042] Yet a further subject matter of the present invention is a
host cell which is transformed with an sbsB gene wherein the sbsB
gene optionally can contain an insertion. The host cell can be a
eukaryotic as well as a prokaryotic cell. The cell is preferably a
prokaryotic organism. Gram-positive organisms e.g. organisms of the
genus bacillus as well as gram-negative organisms such as
enterobacteria in particular E. coli are preferred. Methods for
transforming eukaryotic and prokaryotic cells with nucleic acids
are known and therefore do not need to be elucidated in detail.
[0043] The present invention also concerns an SbsB protein i.e. an
S-layer protein which is coded by a nucleic acid as defined above.
Recombinant SbsB proteins are particularly preferred which contain
one or several peptide or/and polypeptide insertions within the
sbsB sequence. The SbsB part of a polypeptide according to the
invention particularly preferably has a homology of at least 80%
and in particular of at least 90% to the amino acid sequence shown
in SEQ ID NO.6.
[0044] A recombinant S-layer structure can also be assembled from
the recombinant SbsB-S-layer protein molecules analogous to the
recombinant SbsA-S-layer structure. In this structure the
non-modified S-layer proteins are preferably present in a molar
proportion of 10-99% relative to the total S-layer proteins.
[0045] The applications for the recombinant SbsB-S-layer proteins
and S-layer structures according to the invention also correspond
to the applications for SbsA mentioned above. In this connection
its use as a vaccine or adjuvant or as an enzyme reactor is
noteworthy.
[0046] Recombinant S-layer proteins are obtainable by a process in
which
[0047] (a) a host cell is provided which contains a nucleic acid
coding for an S-layer protein which contains a peptide-coding or
polypeptide-coding insertion within the region coding for the
S-layer protein,
[0048] (b) the host cell is cultured under conditions which lead to
an expression of the nucleic acid and to production of the
polypeptide coded by it and
[0049] (c) the resulting polypeptide is isolated from the host cell
or from the culture medium.
[0050] In a first preferred embodiment of this process a
recombinant SbsA-S-layer protein is prepared i.e. the nucleic acid
coding for the recombinant S-layer protein is selected from
[0051] (i) a nucleic acid which comprises the nucleotide sequence
from position 1 to 3684 shown in SEQ ID NO.1 optionally without the
signal peptide-coding section,
[0052] (ii) a nucleic acid which comprises a nucleotide sequence
corresponding to the nucleic acid from (i) within the scope of the
degeneracy of the genetic code and
[0053] (iii) a nucleic acid which comprises a nucleotide sequence
which hybridizes with the nucleic acids from (i) or/and (ii) under
stringent conditions.
[0054] In a second preferred embodiment a recombinant SbsB-S-layer
protein is prepared i.e. the nucleic acid coding for the
recombinant S-layer protein is selected from
[0055] (i) a nucleic acid which comprises the nucleotide sequence
from position 1 to 2763 shown in SEQ ID NO.5 optionally without the
signal peptide-coding section,
[0056] (ii) a nucleic acid which comprises a nucleotide sequence
corresponding to the nucleic acid from (i) within the scope of the
degeneracy of the genetic code and
[0057] (iii) a nucleic acid which comprises a nucleotide sequence
which hybridizes with the nucleic acids from (i) or/and (ii) under
stringent conditions.
[0058] In addition to the recombinant SbsA and SbsB-S-layer
proteins from B.stearothermophilus it is, however, also possible to
prepare recombinant S-layer proteins from other organisms (cf. e.g.
Peyret et al., (1993), supra).
[0059] The recombinant S-layer proteins can on the one hand be
produced in a heterologous host cell i.e. in a host cell which
originally contains no S-layer gene. Examples of such heterologous
host cells are gram-negative prokaryotic organisms such as E.
coli.
[0060] However, the heterologous expression of S-layer proteins can
also take place in gram-positive prokaryotic organisms such as B.
subtilis. For this integration vectors are preferably used which
contain a native or/and a recombinant S-layer gene. When the native
signal sequences are used the S-layer proteins are secreted into
the culture supernatant.
[0061] However, it is often preferable to produce the recombinant
S-layer proteins in homologous host cells i.e. host cells which
originally contain a natural S-layer gene. In one embodiment of
this homologous expression the recombinant S-layer gene is
introduced into the host cell in such a way that the host cell is
still able to express a further S-layer gene which codes for a
non-modified S-layer protein. The non-modified S-layer protein is
preferably capable of forming an S-layer structure that is
compatible with the recombinant S-layer protein. An example of this
embodiment of homologous expression is a B.stearothermophilus PV72
cell which contains intact natural sbsA genes or/and sbsB genes and
is transformed with a plasmid which contains a recombinant
S-layer-gene.
[0062] In a second embodiment the homologous expression can occur
in a host cell in which the intact S-layer gene originally present
has been inactivated. Consequently in this embodiment no further
S-layer gene is expressed in the host cell which codes for a
non-modified S-layer protein which is able to form a compatible
S-layer structure with the recombinant S-layer protein. A specific
example of such a host cell is a B.stearothermophilus PV72 cell in
the genome of which a gene coding for a recombinant S-layer protein
has been introduced, e.g. by homologous recombination, which
replaces the original S-layer gene. A further example of such a
host cell is a B.stearothermophilus cell in which the native
S-layer gene has been inactivated e.g. by site-specific mutagenesis
or/and homologous recombination and is transformed with a vector
containing a recombinant S-layer gene.
[0063] Gram-positive prokaryotic organisms are usually used as host
cells for the homologous expression of recombinant S-layer genes.
B.stearothermophilus PV72 is particularly preferred as a host cell
which can be cultured at a high temperature in a defined synthetic
medium (Schuster et al., (1995), Biotechnol. and Bioeng. 48:
66-77).
[0064] The present invention is further elucidated by the following
examples and figures.
[0065] SEQ ID NO.1 shows the complete nucleotide sequence of the
coding section of the S-layer gene sbsA of
B.stearothermophilus;
[0066] SEQ ID NO.2 shows the amino acid sequence derived
therefrom;
[0067] SEQ ID NO.3 shows the nucleotide sequence of the primer
T5-X;
[0068] SEQ ID NO.4 shows the nucleotide sequence of the primer
E;
[0069] SEQ ID NO.5 shows the complete nucleotide sequence of the
coding section of the S-layer gene sbsB of
B.stearothermophilus;
[0070] SEQ ID NO.6 shows the amino acid sequence derived
therefrom;
[0071] SEQ ID NO.7 shows the nucleotide sequence of a partial
fragment of the streptavidin gene;
[0072] SEQ ID NO.8 shows the nucleotide sequence of the primer NIS
2AG;
[0073] SEQ ID NO.9 shows the nucleotide sequence of the primer LIS
C3;
[0074] FIG. 1 shows a schematic representation of the sbsA PCR
fragment used to prepare the recombinant vector pBK4;
[0075] FIG. 2 shows a schematic representation of peptide
insertions in the amino acid sequence of the SbsA S-layer protein
and
[0076] FIG. 3 shows a schematic representation of amino acid
substitutions and amino acid insertions in recombinant S-layer
proteins.
EXAMPLES
[0077] 1. Bacterial Strains, Media and Plasmids
[0078] Gram-positive bacteria of the strain Bacillus
stearothermophilus PV72 were cultured at 58.degree. C. in SVIII
medium (Bartelmus and Perschak, Z. Zuckerrind. 7 (1957), 276-281).
Bacteria of the strain E. coli pop2135 (endA, thi, hsdr, malT,
cI857, .lambda.pR, malPQ) were cultured in LB medium (Sambrook et
al., (1989), supra). Ampicillin was added to the medium at a final
concentration of 100 .mu.g/ml to select for transformants. The
plasmid pPLcAT10 (.lambda.pL, bla, colE1) (Stanssens et al., Gene
36 (1985), 211-223) was used as the cloning vector.
[0079] 2. Manipulation of DNA Fragments
[0080] Restriction analysis of DNA, agarose gel electrophoresis and
cloning of DNA fragments were carried out according to the standard
methods described in Sambrook et al. (1989), supra.
[0081] Competent cells were transformed by electroporation using a
Bio-Rad gene pulser (Bio-Rad Laboratories, Richmond, Calif. USA)
according to the manufacturer's instructions.
[0082] Plasmid DNA was isolated by the method of Birnboim and Doly
(Nucleic Acids Res. 7 (1979), 1513-1523). Chromosomal DNA was
isolated according to the method described in Ausubel et al.
(Current Protocols in Molecular Biology (1987), New York, John
Wiley).
[0083] Restriction endonucleases and other enzymes were obtained
from Boehringer Mannheim, New England Biolabs or Stratagene and
used according to the manufacturer's instructions.
[0084] 3. DNA Sequencing
[0085] The DNA sequences of the 5' regions and the 3' regions
(including the region coding for the signal sequence) of the gene
sbsA in the vector pPLcAT10 were determined by the dideoxy chain
termination method of Sanger et al. The primers used for sequencing
were constructed on the basis of the already published sbsA
sequence (Kuen et al. Gene 145 (1994), 115-120).
[0086] 4. PCR Amplification of sbsA
[0087] The PCR amplification of the sbsA gene was carried out in a
reaction volume of 100 .mu.l in which 200 .mu.M deoxynucleotides, 1
U Pfu-polymerase (Stratagene), 1.times. Pfu-reaction buffer, 0.5
.mu.M of each oligonucleotide primer and 100 ng genomic DNA from
B.stearothermophilus as a template were present. The amplification
was carried out for 30 cycles in a thermocycler (Biomed
thermocycler 60). Each cycle was composed of a denaturing step of
1.5 min at 95.degree. C., an annealing step of 1 min at 56.degree.
C. and 1 min at 50.degree. C. as well as an extension step of 2 min
at 72.degree. C.
[0088] The primer T5-X shown in the sequence protocol as SEQ ID
NO.3 which flanks the 5' region of sbsA and contains an XbaI site
and the primer E shown in the sequence protocol in SEQ ID NO.4
which flanks the 20 nucleotide upstream region of the transcription
terminator of the sbsA sequence and contains a BamHI site were used
as primers.
[0089] The products amplified by PCR were electrophoretically
separated on a 0.8% agarose gel and purified for cloning using the
system from Gene Clean (BIO101 La Jolla, Calif. USA).
[0090] 5. Cloning of the sbsA Gene into the Vector pPLcAT10
[0091] The sbsA gene obtained by PCR with a length of 3.79 kb was
purified and cleaved with the restriction endonucleases XbaI and
BamHI. The resulting XbaI-BamHI fragment was cloned into the
corresponding restriction sites of the vector pPLcAT10 so that the
sbsA gene was under transcriptional control of the pL promoter
located upstream. The ATG start codon of the sbsA sequence was
reconstructed by the cloning procedure. The cloned sbsA sequence
contained the N-terminal signal sequence of sbsA and ended 20 nt
after the transcription terminator. After ligation of the vector
DNA with the sbsA fragment, the E. coli strain pop2135 was
transformed by electrotransformation. The resulting clones were
subjected to a DNA restriction analysis. A positive clone was
sequenced in order to verify the correct sequence transitions at
the 5' and 3' ends. This clone was named pBK4.
[0092] A schematic representation of the 3.79 kb XbaI sbsA fragment
and its location in the multiple cloning site of the plasmid pBK4
is shown in FIG. 1 (abbreviations: tT: transcription terminator;
ori: origin of the DNA replication; amp: ampicillin resistance
gene).
[0093] 6. Recombinant Expression of the SbsA Gene in E. coli
[0094] E. coli pop2135/pBK4 cells were cultured at 28.degree. C.
until an optical density OD.sub.600 of 0.3 was reached. Then the
expression of sbsA was induced by increasing the culture
temperature from 28.degree. C. to 42.degree. C. 1.5 ml aliquots
were taken before and 1, 2, 3 and 5 hours after induction of the
sbsA expression. E. coli pop2135/pPLcAT10 (cultured under the same
conditions) and B.stearothermophilus PV72 were used as
controls.
[0095] Culture supernatants and cell extracts from all samples were
examined for the expression of S-layer proteins by SDS-PAGE and
Western immunoblotting.
[0096] An additional strong protein band with the same molecular
weight as the wild type SbsA protein was found in extracts from E.
coli cells transformed with pBK4. No degradation products of SbsA
itself were found in a period of up to 5 hours after induction of
expression. Thus presumably the S-layer protein sbsA is stable in
E. coli and is not degraded by proteases.
[0097] A densitometric determination of the relative amount of SbsA
protein was carried out. At a time point of 4 hours after induction
the sbsA protein was in a proportion of ca. 16% relative to the
total cellular protein.
[0098] The SbsA protein produced in E. coli migrated in the SDS gel
slightly more slowly than the natural SbsA protein from
B.stearothermophilus. Experiments to determine the N-terminal amino
acid sequence of the SbsA protein by Edman degradation were not
successful due to a blocking of the N-terminus. Thus presumably the
signal sequence was not cleaved in E. coli.
[0099] A Western blot analysis of total cell extracts and culture
supernatants of E. coli/pBK4 also only yielded a single
sbsA-specific protein band with a slightly higher molecular weight
than wild type SbsA protein from stearothermophilus.
[0100] For the Western blot the proteins were transferred onto a
nitrocellulose membrane and incubated with a polyclonal antiserum
against SbsA from rabbits. The preparation of this antiserum is
described in Egelseer et al. (J. Bacteriol. 177 (1995), 1444-1451).
A conjugate of goat anti-rabbit IgG and alkaline phosphatase was
used to detect bound SbsA-specific antibodies.
[0101] No SbsA protein could be detected from supernatants from E.
coli cells transformed with pBK4 even after induction of sbsA gene
expression. This shows that SbsA is not exported into the
surrounding medium.
[0102] 7. Location and Organisation of the S-layer Protein SbsA in
the Cytoplasm of E. coli
[0103] Cells of E. coli pop2135/pBK4 which were harvested from
cultures 1, 2, 3 and 5 hours after induction of the S-layer protein
expression were examined for the intracellular organisation of
sbsA. Non-induced cells cultured at 28.degree. C. and cells of
B.stearothermophilus PV72 were examined as controls.
[0104] For this whole cells of both organisms were fixed and
embedded in detection resin according to the method of Messner et
al. (Int. J.Syst.Bacteriol. 34 (1984), 202-210). Subsequently
ultrathin sections of the embedded preparations were prepared and
stained with uranyl acetate.
[0105] The cytoplasm of non-induced E. coli cells exhibited the
typical granular structure which did not change even when the OD of
the suspensions increased. Longitudinal sections of E. coli cells
which were harvested 1 hour after induction of the S-layer protein
expression exhibited parallel, leaf-like structures in the
cytoplasm. From cross sections it was apparent that these
structures have a concentric arrangement.
[0106] The amount of leaf-like structures considerably increased
between 1 and 2 hours after induction of the sbsA expression and
afterwards remained essentially constant.
[0107] The sbsA protein recombinantly produced in E. coli could
also be detected by immunogold labelling with sbsA-specific
antibodies. An ordered structure of the recombinantly produced SbsA
protein was also found with this detection method.
[0108] It was clearly apparent from these morphological data that
the SbsA protein did not aggregate to form irregular inclusion
bodies but rather formed monomolecular S-layer crystals. A
remarkable property of the SbsA-S-layer layers assembled in E. coli
was the concentric arrangement at defined distances. The presence
of the signal sequence did not interfere with correct assembly.
[0109] 8. Preparation of Recombinant sbsA-S-Layer Genes
[0110] 8.1 Insertion of a 6 bp Long DNA Sequence
[0111] A modified kanamycin cassette (1.3 kb) was used for the
site-specific insertion mutagenesis of the sbsA gene which was
isolated by cleavage of the plasmid pWJC3 (obtained from W. T.
McAllister, New York) by SmaI. The cassette was ligated into five
different blunt-ended restriction sites of the sbsA gene, i.e. into
the NruI site at position bp 582 (pSL582), into the SnaBI site at
position bp 917 (pSL917) and into each of the PvuII sites at
positions bp 878 (pSL878), bp 2504 (pSL2504) and bp 2649 (pSL2649).
After selection of kanamycin-resistant clones, the cassette was
removed from the insertion site by cleavage with ApaI followed by a
religation of the S-layer plasmid pBK4. The cutting out and
religation procedure left an insertion of 6 bp CCCGGG (ApaI
restriction site). The system of this linker insertion is shown
schematically in FIG. 2.
[0112] The resulting recombinant S-layer genes code for modified
sbsA proteins elongated by 2 amino acids.
[0113] The specific changes in the primary structure of the sbsA
proteins are shown in FIG. 3. In the clone pSL582 the insertion led
to the incorporation of glycine and proline between the amino acids
194 and 195 at the N-terminus of the SbsA protein. The amino acids
alanine and arginine were inserted in the clone pSL917 between the
amino acids 306 and 307. In the clone pSL2649 glycine and proline
were inserted between the amino acids at positions 883 and 884. An
insertion of alanine and proline between the amino acids 293 and
294 was obtained in the clone pSL878. Furthermore the alanine at
position 293 was substituted by glycine. In the clone pSL2504 the
amino acids alanine and proline were inserted between the amino
acids 835 and 836 and the alanine at position 835 was replaced by
glycine.
[0114] All clones obtained by insertion mutagenesis retained their
ability to synthesise the S-layer protein.
[0115] In order to test the ability of the modified proteins to
assemble into S-layer structures, ultrathin longitudinal sections
of whole cells which had been cultured for 4 hours under inductive
conditions were prepared according to the procedure described in
section 7. It was found that the cytoplasm of all five clones is
filled with parallel, leaf-like structures which follow the curve
of the cell poles. There were no morphological differences of the
cytoplasm in the 5 different clones examined. Exactly the same
leaf-like structures were found as in the assembly of the wild type
SbsA protein in E. coli (section 7).
[0116] 8.2 Insertion of a DNA Sequence Coding for Streptavidin
[0117] In order to examine whether the insertion of larger protein
sequences into the SbsA protein can also be tolerated, a DNA
fragment coding for a part of streptavidin (160 amino acids)
provided with ApaI linkers (SEQ ID NO.7) was gene inserted into the
ApaI restriction site of the sbsA clones pSL582, pSL878, pSL917 and
pSL2649 prepared in the example on page 1. The streptavidin
sequence was inserted in SL582 in the codon 197, in pSL878 between
codon 295 and 296, in pSL917 in the codon 308 and 309 and in
pSL2649 in the codon 886. It was possible to detect the expression
of SbsA-streptavidin fusion proteins in all constructs by SDS-PAGE
and immunoblots. It was found by EM analysis that a self assembly
of the S-layer structure was possible in the fusion proteins
containing insertions in the codon 197 and between the codons 295
and 296.
[0118] The SbsA-streptavidin fusion proteins can be isolated as
monomers and reassembled to form homogeneous SbsA-streptavidin
S-layers or mixed SbsA-streptavidin/SbsA-S-layers. They can be used
to bind biotinylated substances as well as to determine the binding
capacity of enzymes and other bound molecules.
[0119] 8.3 Insertion of a DNA Sequence Coding for BetvI
[0120] A DNA sequence coding for the open reading frame of BetvI
(161 amino acids) the main pollen allergen of the birch (Ferreira
et al., J. Biol. Chem. 268 (1993), 19574-19580) was inserted at the
ApaI site into the sbsA clone pSL878. It was possible to detect the
expression of an SbsA-BetvI fusion protein which contained an
immunologically active BetvI domain.
[0121] The resulting fusion protein can be used for therapeutic or
diagnostic purposes. Hence it can be attempted by administration of
the fusion protein to convert a T.sub.H2-directed IgE antibody
reaction into a T.sub.H1-mediated reaction against BetvI. In this
manner it is possible to suppress the occurrence of symptoms of a
pollen allergy. Furthermore SbsA-BetvI fusion proteins can be used
to test for anti-BetvI antibody concentrations or/and to reduce
high concentrations of anti-BetvI IgE.
[0122] 8.4 Insertion of a DNA Sequence Coding for a Pseudorabies
Virus Antigen
[0123] The DNA sequence coding for the gB epitope SmaBB (255 amino
acids) (nucleotides 489-1224 corresponding to the coordinates
according to the EMBL-Seq: HEHSSGP2) from the pseudorabies virus
was inserted into SSPI site of the sbsA gene after nt 3484 (between
codon 1161 and 1162). It was possible to detect the expression of
SbsA-SmaBB fusion proteins.
[0124] The fusion proteins can be used to test gB-specific immune
reactions. A Western blot analysis using a monoclonal antibody
which corresponds to the inserted sequence showed the immunological
activity of the viral domain within the recombinant SbsA-SmaBB
proteins.
[0125] 8.5 Insertion of a DNA Sequence Coding for the PHB Synthase
(PhbC) from Alcaligenes Eutrophus H16
[0126] A regular arrangement of polypeptide structures with
enzymatic activity on the surface of S-layers is an important goal
in the production of immobilized enzymes within a living cell and
in the case of the 590 amino acid long PHB synthase for the
production of a molecular machine for biopolymer synthesis.
[0127] The phbC gene was isolated by PCR from the plasmid p4A
(Janes et al., Molecular characterisation of the
poly-.beta.-hydroxy-butyrate biosynthesis in Alcaligenes eutrophus
H16. In: Novel Biodegradable Microbial Polymers (publisher Daves,
E. A.), pp 175-190 (1990), Kluver, Dordrecht) as a 1770 nt long DNA
fragment (corresponding to an open reading frame of 590 amino
acids) and inserted into the ApaI cleavage site of the sbsA clone
pSL878 to obtain the plasmid pSbsA-PhbC. It was possible to detect
the expression of an SbsA-PhbC fusion protein of ca. 195 kD in an
E. coli cell transformed with this plasmid. When two copies of the
phbc gene were inserted one behind the other into the ApaI site of
pSL878, it was possible to detect the expression of a fusion
protein of ca. 260 kD.
[0128] For a functional test of the enzymatic activity of the
SbsA-PhbC construct, the E. coli cells which contained the plasmid
pSbsA-PhbC were co-transformed with the plasmid pUMS which contains
the .beta.-ketothiolase (PhbA) and the acetoacetyl-CoA reductase
(PhbB) from A. eutrophus (Kalousek et al., Genetic engineering of
PHB-synthase from Alcaligenes eutrophus H16. In: Proceedings of the
International Symposium on Bacterial Polyhydroxy-alkanoates, pp
426-427 (1993), publisher Schlegel H. G., Steinbuchel A. Goltze
Press, Gottingen). The poly-.beta.-hydroxybutyrate formation in the
co-transformed E. coli cells was detectable by staining with Sudan
black, gas chromatography and electron microscopy. These findings
show that the SbsA-PhbC construct is enzymatically active and
represents a successful example of the immobilization of enzymes on
intracellular S-layer matrices.
[0129] 8.6 Insertion of a DNA Sequence Coding for a Bacterial
Luciferase Gene
[0130] A monocistronic LuxAB gene with a length of 2,070 nt which
contains the fusion protein LuxAB composed of the two subunits LuxB
and LuxB of the bacterial luciferase from Vibrio harveyi was
isolated from the plasmid pT7-mut3 (Boylan et al., J. Biol. Chem.
264 (1989), 1915-1918) by PCR and inserted into the ApaI site of
the clone pSL878 prepared in example 8.1 to obtain the plasmid
pBK878-LuxAB. It was possible to detect the expression of an
SbsA-PhbC fusion protein of ca. 207 kD in an E. coli cell
transformed with this plasmid. The enzymatic activity of,the fusion
protein was demonstrated by the method described in Boylan et al.,
Supra.
[0131] 9. Isolation and Characterization of the SbsB Gene
[0132] The basis for the isolation of the sbsB gene was the amino
acid sequence of the N-terminus as well as the sequence of three
internal peptides of the SbsB protein. Starting with these peptide
sequences, degenerate oligonucleotide primers were constructed and
used for the PCR. In this manner a 1076 bp long PCR fragment from
the chromosomal DNA of B.stearothermophilus was amplified, cloned
and sequenced (corresponding to position 100-1176 of the sequence
shown in SEQ ID No.5).
[0133] The method of inverse PCR was used to amplify the sections
on the 5' side and 3' side of the sbsB gene and stepwise
overlapping DNA fragments were obtained with the aid of various
primer combinations and sequenced.
[0134] The primer NIS 2AG shown in the sequence protocol as SEQ ID
NO.8 which contains the 5' region of sbsB as well as the primer LIS
C3 shown in the. sequence protocol of SEQ ID NO.9 which contains
the 3' region of sbsB were used as primers to amplify the complete
sbsB gene.
[0135] The PCR fragment obtained in this manner which contains the
nucleotide sequence shown in SEQ ID NO.5 with 5' and 3' BamHI
restriction cleavage sites was cloned as described in example 5
into the vector pPLcAT10 in which the expression takes place under
the control of the lambda PL promoter.
[0136] Furthermore the sbsB-PCR fragment with the 5' side EcoRI and
3' side BamHi cleavage site were cloned into the vector pUC18 in
which the expression took place under the control of the lac
promoter.
[0137] The detection of the sbsB expression was carried out as
described in examples 6 and 7 by SDS gel electrophoresis and
electron microscopy.
[0138] 10. Preparation of Recombinant SbsB-S-layer Genes
[0139] Recombinant sbsB genes were prepared analogously to the
methods described in example 8.
[0140] Thus in accordance with the method described in example 8.1,
a 6 nt long DNA sequence containing an ApaI restriction cleavage
site was introduced at various positions into the sbsB-layer gene.
The recombinant sbsB clones pAK407, pAK481 and pAK1582 with ApaI
cleavage sites at nt 407 (codon 136), 481 (codon 161/162) and 1582
(codon 528/529) were obtained in this manner. These clones obtained
by insertion mutagenesis retained their ability to synthesize the
S-layer protein and form S-layer structures.
[0141] Analogously to the method described in example 8.2, a DNA
fragment coding for streptavidin was inserted into the ApaI
restriction sites of the sbsB clones pAK407 and pAK481.
[0142] Analogously to example 8.4, a DNA sequence coding for the gB
epitope SmaBB was inserted into the ApaI cleavage sites of the sbsB
clones pAK481 and pAK1582. It was possible to detect the expression
of sbsB-SmaB fusion proteins of ca. 130 kD in the E. coli cells
transformed with the resulting recombinant plasmids. When two
copies of the SmaBB epitopes were inserted one behind the other
into the ApaI cleavage site of pAK481 it was possible to detect the
expression of a fusion protein of ca. 157 kD. The SmaBB domains of
the fusion proteins were recognized by specific antibodies.
[0143] Analogously to example 8.6 it was possible to detect the
expression of a 175 kD SbsB-LuxAB fusion protein when the LuxAB
sequence was inserted into the ApaI cleavage site of pAK407.
[0144] 11. Heterologous Expression of sbsA and sbsB in Bacillus
subtilis
[0145] The integration vector pX (Kim, L., Mogk, A. and Schumann
W., Gene 181 (1996), 71-76: A xylose-inducible Bacillus subtilis
integration vector and its application) was used for the
heterologous expression of sbsA and sbsB in B. subtilis. The
S-layer genes in the resulting recombinant expression vectors are
under the transcriptional control of the xyl promoter.
Transformants of B.subtilis containing an S-layer gene integrated
in the chromosome exhibited an expression of large amounts of
S-layer proteins in the supernatant of the cells which was
inducible by addition of xylose to the growth medium. This shows
that the signal sequences of sbsA and sbsB are recognized by the B.
subtilis cell.
[0146] In an analogous manner it was possible to achieve a
heterologous expression of recombinant sbsA and sbsB layer genes in
B. subtilis.
Sequence CWU 1
1
10 1 3687 DNA Bacillus stearothermophilus CDS (1)..(3684)
sig_peptide (1)..(90) mat_peptide (91)..(3684) 1 atg gat agg aaa
aaa gct gtg aaa cta gca aca gca agt gct att gca 48 Met Asp Arg Lys
Lys Ala Val Lys Leu Ala Thr Ala Ser Ala Ile Ala -30 -25 -20 -15 gca
agt gca ttt gtc gct gca aat cca aac gct tct gaa gcg gct aca 96 Ala
Ser Ala Phe Val Ala Ala Asn Pro Asn Ala Ser Glu Ala Ala Thr -10 -5
-1 1 gat gta gca aca gta gta agc caa gca aaa gca cag ttc aaa aaa
gca 144 Asp Val Ala Thr Val Val Ser Gln Ala Lys Ala Gln Phe Lys Lys
Ala 5 10 15 tac tat act tac agc cat aca gta acg gaa act ggt gaa ttc
cca aac 192 Tyr Tyr Thr Tyr Ser His Thr Val Thr Glu Thr Gly Glu Phe
Pro Asn 20 25 30 att aac gat gta tat gct gaa tac aac aaa gcg aaa
aaa cga tac cgt 240 Ile Asn Asp Val Tyr Ala Glu Tyr Asn Lys Ala Lys
Lys Arg Tyr Arg 35 40 45 50 gat gcg gta gca tta gtg aat aaa gca ggt
ggc gcg aaa aaa gac gct 288 Asp Ala Val Ala Leu Val Asn Lys Ala Gly
Gly Ala Lys Lys Asp Ala 55 60 65 tac tta gct gat tta caa aaa gaa
tat gaa act tac gtt ttc aaa gca 336 Tyr Leu Ala Asp Leu Gln Lys Glu
Tyr Glu Thr Tyr Val Phe Lys Ala 70 75 80 aac cct aaa tct ggc gaa
gct cgt gta gca act tac atc gat gct tac 384 Asn Pro Lys Ser Gly Glu
Ala Arg Val Ala Thr Tyr Ile Asp Ala Tyr 85 90 95 aac tat gca aca
aaa tta gac gaa atg cgc caa gag cta gag gct gct 432 Asn Tyr Ala Thr
Lys Leu Asp Glu Met Arg Gln Glu Leu Glu Ala Ala 100 105 110 gtt caa
gca aaa gat tta gaa aaa gca gaa caa tac tat cac aaa att 480 Val Gln
Ala Lys Asp Leu Glu Lys Ala Glu Gln Tyr Tyr His Lys Ile 115 120 125
130 cct tat gaa att aaa act cgc aca gtc att tta gat cgc gta tat ggt
528 Pro Tyr Glu Ile Lys Thr Arg Thr Val Ile Leu Asp Arg Val Tyr Gly
135 140 145 aaa aca act cgt gat tta ctt cgc tct aca ttt aaa gca aaa
gca caa 576 Lys Thr Thr Arg Asp Leu Leu Arg Ser Thr Phe Lys Ala Lys
Ala Gln 150 155 160 gaa ctt cgc gac agc tta att tat gat att acc gtt
gca atg aaa gcg 624 Glu Leu Arg Asp Ser Leu Ile Tyr Asp Ile Thr Val
Ala Met Lys Ala 165 170 175 cgc gaa gta caa gac gct gtg aaa gca ggc
aat tta gac aaa gct aaa 672 Arg Glu Val Gln Asp Ala Val Lys Ala Gly
Asn Leu Asp Lys Ala Lys 180 185 190 gct gct gtt gat caa atc aat caa
tac tta cca aaa gta aca gat gct 720 Ala Ala Val Asp Gln Ile Asn Gln
Tyr Leu Pro Lys Val Thr Asp Ala 195 200 205 210 ttc aaa act gaa cta
aca gaa gta gcg aaa aaa gca tta gat gca gat 768 Phe Lys Thr Glu Leu
Thr Glu Val Ala Lys Lys Ala Leu Asp Ala Asp 215 220 225 gaa gct gcg
ctt act cca aaa gtt gaa agt gta agt gcg att aac act 816 Glu Ala Ala
Leu Thr Pro Lys Val Glu Ser Val Ser Ala Ile Asn Thr 230 235 240 caa
aac aaa gct gtt gaa tta aca gca gta cca gtg aac gga aca cta 864 Gln
Asn Lys Ala Val Glu Leu Thr Ala Val Pro Val Asn Gly Thr Leu 245 250
255 aaa tta caa ctt tca gct gct gca aat gaa gat aca gta aac gta aat
912 Lys Leu Gln Leu Ser Ala Ala Ala Asn Glu Asp Thr Val Asn Val Asn
260 265 270 act gta cgt atc tat aaa gtg gac ggt aac att cca ttt gcc
ctt aat 960 Thr Val Arg Ile Tyr Lys Val Asp Gly Asn Ile Pro Phe Ala
Leu Asn 275 280 285 290 acg gca gat gtt tct tta tct aca gac gga aaa
act atc act gtg gat 1008 Thr Ala Asp Val Ser Leu Ser Thr Asp Gly
Lys Thr Ile Thr Val Asp 295 300 305 gct tca act cca ttc gaa aat aat
acg gag tat aaa gta gta gtt aaa 1056 Ala Ser Thr Pro Phe Glu Asn
Asn Thr Glu Tyr Lys Val Val Val Lys 310 315 320 ggt att aaa gac aaa
aat ggc aaa gaa ttt aaa gaa gat gca ttc act 1104 Gly Ile Lys Asp
Lys Asn Gly Lys Glu Phe Lys Glu Asp Ala Phe Thr 325 330 335 ttc aag
ctt cga aat gat gct gta gtt act caa gtg ttt gga act aat 1152 Phe
Lys Leu Arg Asn Asp Ala Val Val Thr Gln Val Phe Gly Thr Asn 340 345
350 gta aca aac aac act tct gta aac tta gca gca ggt act ttc gac act
1200 Val Thr Asn Asn Thr Ser Val Asn Leu Ala Ala Gly Thr Phe Asp
Thr 355 360 365 370 gac gat act tta aca gta gta ttt gat aag ttg tta
gca cct gaa act 1248 Asp Asp Thr Leu Thr Val Val Phe Asp Lys Leu
Leu Ala Pro Glu Thr 375 380 385 gta aac agc tcg aac gtt act att aca
gat gtt gaa act gga aaa cgc 1296 Val Asn Ser Ser Asn Val Thr Ile
Thr Asp Val Glu Thr Gly Lys Arg 390 395 400 att cca gta att gca tct
act tct ggt tct aca att act att acg tta 1344 Ile Pro Val Ile Ala
Ser Thr Ser Gly Ser Thr Ile Thr Ile Thr Leu 405 410 415 aaa gaa gcg
tta gta act ggt aaa caa tat aaa ctt gct atc aat aat 1392 Lys Glu
Ala Leu Val Thr Gly Lys Gln Tyr Lys Leu Ala Ile Asn Asn 420 425 430
gtt aaa aca tta act ggt tac aat gca gaa gct tac gag tta gtg ttc
1440 Val Lys Thr Leu Thr Gly Tyr Asn Ala Glu Ala Tyr Glu Leu Val
Phe 435 440 445 450 act gca aac gca tca gca cca act gtt gct acc gct
cct act act tta 1488 Thr Ala Asn Ala Ser Ala Pro Thr Val Ala Thr
Ala Pro Thr Thr Leu 455 460 465 ggt ggt aca act tta tct act ggt tct
ctt aca aca aat gtt tgg ggt 1536 Gly Gly Thr Thr Leu Ser Thr Gly
Ser Leu Thr Thr Asn Val Trp Gly 470 475 480 aaa ttg gct ggt ggt gtg
aat gaa gct gga act tat tat cct ggt ctt 1584 Lys Leu Ala Gly Gly
Val Asn Glu Ala Gly Thr Tyr Tyr Pro Gly Leu 485 490 495 caa ttc aca
aca acg ttt gct act aag tta gac gaa tct act tta gct 1632 Gln Phe
Thr Thr Thr Phe Ala Thr Lys Leu Asp Glu Ser Thr Leu Ala 500 505 510
gat aac ttt gta tta gtt gaa aaa gaa tct ggt aca gtt gtt gct tct
1680 Asp Asn Phe Val Leu Val Glu Lys Glu Ser Gly Thr Val Val Ala
Ser 515 520 525 530 gaa cta aaa tat aat gca gac gct aaa atg gta act
tta gtg cca aaa 1728 Glu Leu Lys Tyr Asn Ala Asp Ala Lys Met Val
Thr Leu Val Pro Lys 535 540 545 gcg gac ctt aaa gaa aat aca atc tat
caa atc aaa att aaa aaa ggc 1776 Ala Asp Leu Lys Glu Asn Thr Ile
Tyr Gln Ile Lys Ile Lys Lys Gly 550 555 560 ttg aag tcc gat aaa ggt
att gaa tta ggc act gtt aac gag aaa aca 1824 Leu Lys Ser Asp Lys
Gly Ile Glu Leu Gly Thr Val Asn Glu Lys Thr 565 570 575 tat gag ttc
aaa act caa gac tta act gct cct aca gtt att agc gta 1872 Tyr Glu
Phe Lys Thr Gln Asp Leu Thr Ala Pro Thr Val Ile Ser Val 580 585 590
acg tct aaa aat ggc gac gct gga tta aaa gta act gaa gct caa gaa
1920 Thr Ser Lys Asn Gly Asp Ala Gly Leu Lys Val Thr Glu Ala Gln
Glu 595 600 605 610 ttt act gtg aag ttc tca gag aat tta aat aca ttt
aat gct aca acc 1968 Phe Thr Val Lys Phe Ser Glu Asn Leu Asn Thr
Phe Asn Ala Thr Thr 615 620 625 gtt tcg ggt agc aca atc aca tac ggt
caa gtt gct gta gta aaa gcg 2016 Val Ser Gly Ser Thr Ile Thr Tyr
Gly Gln Val Ala Val Val Lys Ala 630 635 640 ggt gca aac tta tct gct
ctt aca gca agt gac atc att cca gct agt 2064 Gly Ala Asn Leu Ser
Ala Leu Thr Ala Ser Asp Ile Ile Pro Ala Ser 645 650 655 gtt gaa gcg
gtt act ggt caa gat gga aca tac aaa gtg aaa gtt gct 2112 Val Glu
Ala Val Thr Gly Gln Asp Gly Thr Tyr Lys Val Lys Val Ala 660 665 670
gct aac caa tta gaa cgt aac caa ggg tac aaa tta gta gtg ttc ggt
2160 Ala Asn Gln Leu Glu Arg Asn Gln Gly Tyr Lys Leu Val Val Phe
Gly 675 680 685 690 aaa ggt gca aca gct cct gtt aaa gat gct gca aat
gca aat act tta 2208 Lys Gly Ala Thr Ala Pro Val Lys Asp Ala Ala
Asn Ala Asn Thr Leu 695 700 705 gca act aac tat atc tat aca ttt aca
act gaa ggt caa gac gta aca 2256 Ala Thr Asn Tyr Ile Tyr Thr Phe
Thr Thr Glu Gly Gln Asp Val Thr 710 715 720 gca cca acg gtt aca aaa
gta ttc aaa ggt gat tct tta aaa gac gct 2304 Ala Pro Thr Val Thr
Lys Val Phe Lys Gly Asp Ser Leu Lys Asp Ala 725 730 735 gat gca gtt
act aca ctt acg aac gtt gat gca ggt caa aaa ttc act 2352 Asp Ala
Val Thr Thr Leu Thr Asn Val Asp Ala Gly Gln Lys Phe Thr 740 745 750
atc caa ttt agc gaa gaa tta aaa act tct agt ggt tct tta gtg ggt
2400 Ile Gln Phe Ser Glu Glu Leu Lys Thr Ser Ser Gly Ser Leu Val
Gly 755 760 765 770 ggc aaa gta act gtc gag aaa tta aca aac aac gga
tgg gta gat gct 2448 Gly Lys Val Thr Val Glu Lys Leu Thr Asn Asn
Gly Trp Val Asp Ala 775 780 785 ggt act gga aca act gta tca gtt gct
cct aag aca gat gca aat ggt 2496 Gly Thr Gly Thr Thr Val Ser Val
Ala Pro Lys Thr Asp Ala Asn Gly 790 795 800 aaa gta aca gct gct gtg
gtt aca tta act ggt ctt gac aat aac gac 2544 Lys Val Thr Ala Ala
Val Val Thr Leu Thr Gly Leu Asp Asn Asn Asp 805 810 815 aaa gat gcg
aaa ttg cgt ctg gta gta gat aag tct tct act gat gga 2592 Lys Asp
Ala Lys Leu Arg Leu Val Val Asp Lys Ser Ser Thr Asp Gly 820 825 830
att gct gat gta gct ggt aat gta att aag gaa aaa gat att tta att
2640 Ile Ala Asp Val Ala Gly Asn Val Ile Lys Glu Lys Asp Ile Leu
Ile 835 840 845 850 cgt tac aac agc tgg aga cac act gta gct tct gtg
aaa gct gct gct 2688 Arg Tyr Asn Ser Trp Arg His Thr Val Ala Ser
Val Lys Ala Ala Ala 855 860 865 gac aaa gat ggt caa aac gct tct gct
gca ttc cca aca agc act gca 2736 Asp Lys Asp Gly Gln Asn Ala Ser
Ala Ala Phe Pro Thr Ser Thr Ala 870 875 880 att gat aca act aag agc
tta tta gtt gaa ttc aat gaa act gat tta 2784 Ile Asp Thr Thr Lys
Ser Leu Leu Val Glu Phe Asn Glu Thr Asp Leu 885 890 895 gcg gaa gtt
aaa cct gag aac atc gtt gtt aaa gat gca gca ggt aat 2832 Ala Glu
Val Lys Pro Glu Asn Ile Val Val Lys Asp Ala Ala Gly Asn 900 905 910
gcg gta gct ggt act gta aca gca tta gac ggt tct aca aat aaa ttt
2880 Ala Val Ala Gly Thr Val Thr Ala Leu Asp Gly Ser Thr Asn Lys
Phe 915 920 925 930 gta ttc act cca tct caa gaa tta aaa gct ggt aca
gtt tac tct gta 2928 Val Phe Thr Pro Ser Gln Glu Leu Lys Ala Gly
Thr Val Tyr Ser Val 935 940 945 aca att gac ggt gtg aga gat aaa gta
ggt aac aca atc tct aaa tac 2976 Thr Ile Asp Gly Val Arg Asp Lys
Val Gly Asn Thr Ile Ser Lys Tyr 950 955 960 att act tcg ttc aag act
gta tct gcg aat cca acg tta tct tca atc 3024 Ile Thr Ser Phe Lys
Thr Val Ser Ala Asn Pro Thr Leu Ser Ser Ile 965 970 975 agc att gct
gac ggt gca gtt aac gtt gac cgt tct aaa aca att aca 3072 Ser Ile
Ala Asp Gly Ala Val Asn Val Asp Arg Ser Lys Thr Ile Thr 980 985 990
att gaa ttc agc gat tca gtt cca aac cca aca atc act ctt aag aag
3120 Ile Glu Phe Ser Asp Ser Val Pro Asn Pro Thr Ile Thr Leu Lys
Lys 995 1000 1005 1010 gct gac gga act tca ttt act aat tac act tta
gta aat gta aat aat 3168 Ala Asp Gly Thr Ser Phe Thr Asn Tyr Thr
Leu Val Asn Val Asn Asn 1015 1020 1025 gaa aat aaa aca tac aaa att
gta ttc cac aaa ggt gta aca ctt gac 3216 Glu Asn Lys Thr Tyr Lys
Ile Val Phe His Lys Gly Val Thr Leu Asp 1030 1035 1040 gag ttt act
caa tat gag tta gca gtt tca aaa gat ttt caa act ggt 3264 Glu Phe
Thr Gln Tyr Glu Leu Ala Val Ser Lys Asp Phe Gln Thr Gly 1045 1050
1055 act gat att gat agc aaa gtt aca ttc atc aca ggt tct gtt gct
act 3312 Thr Asp Ile Asp Ser Lys Val Thr Phe Ile Thr Gly Ser Val
Ala Thr 1060 1065 1070 gac gaa gta aaa cct gct cta gta ggc gtt ggt
tca tgg aat gga aca 3360 Asp Glu Val Lys Pro Ala Leu Val Gly Val
Gly Ser Trp Asn Gly Thr 1075 1080 1085 1090 agc tat act cag gat gct
gca gca aca cga ctt cgg tct gta gct gac 3408 Ser Tyr Thr Gln Asp
Ala Ala Ala Thr Arg Leu Arg Ser Val Ala Asp 1095 1100 1105 ttc gtt
gcg gag cca gtt gcc ctt caa ttc tca gaa ggt atc gat tta 3456 Phe
Val Ala Glu Pro Val Ala Leu Gln Phe Ser Glu Gly Ile Asp Leu 1110
1115 1120 acg aat gca act gtg aca gta aca aat att act gat gat aaa
act gtt 3504 Thr Asn Ala Thr Val Thr Val Thr Asn Ile Thr Asp Asp
Lys Thr Val 1125 1130 1135 gaa gtt att tca aaa gag agt gta gac gca
gac cat gat gca ggt gct 3552 Glu Val Ile Ser Lys Glu Ser Val Asp
Ala Asp His Asp Ala Gly Ala 1140 1145 1150 act aag gag aca tta gta
att aac aca gtt act cct tta gta ctt gat 3600 Thr Lys Glu Thr Leu
Val Ile Asn Thr Val Thr Pro Leu Val Leu Asp 1155 1160 1165 1170 aac
agc aag act tat aag att gtt gta agt gga gtt aaa gat gca gca 3648
Asn Ser Lys Thr Tyr Lys Ile Val Val Ser Gly Val Lys Asp Ala Ala
1175 1180 1185 ggt aat gtt gca gat act att aca ttc tat att aag taa
3687 Gly Asn Val Ala Asp Thr Ile Thr Phe Tyr Ile Lys 1190 1195 2
1228 PRT Bacillus stearothermophilus 2 Met Asp Arg Lys Lys Ala Val
Lys Leu Ala Thr Ala Ser Ala Ile Ala -30 -25 -20 -15 Ala Ser Ala Phe
Val Ala Ala Asn Pro Asn Ala Ser Glu Ala Ala Thr -10 -5 -1 1 Asp Val
Ala Thr Val Val Ser Gln Ala Lys Ala Gln Phe Lys Lys Ala 5 10 15 Tyr
Tyr Thr Tyr Ser His Thr Val Thr Glu Thr Gly Glu Phe Pro Asn 20 25
30 Ile Asn Asp Val Tyr Ala Glu Tyr Asn Lys Ala Lys Lys Arg Tyr Arg
35 40 45 50 Asp Ala Val Ala Leu Val Asn Lys Ala Gly Gly Ala Lys Lys
Asp Ala 55 60 65 Tyr Leu Ala Asp Leu Gln Lys Glu Tyr Glu Thr Tyr
Val Phe Lys Ala 70 75 80 Asn Pro Lys Ser Gly Glu Ala Arg Val Ala
Thr Tyr Ile Asp Ala Tyr 85 90 95 Asn Tyr Ala Thr Lys Leu Asp Glu
Met Arg Gln Glu Leu Glu Ala Ala 100 105 110 Val Gln Ala Lys Asp Leu
Glu Lys Ala Glu Gln Tyr Tyr His Lys Ile 115 120 125 130 Pro Tyr Glu
Ile Lys Thr Arg Thr Val Ile Leu Asp Arg Val Tyr Gly 135 140 145 Lys
Thr Thr Arg Asp Leu Leu Arg Ser Thr Phe Lys Ala Lys Ala Gln 150 155
160 Glu Leu Arg Asp Ser Leu Ile Tyr Asp Ile Thr Val Ala Met Lys Ala
165 170 175 Arg Glu Val Gln Asp Ala Val Lys Ala Gly Asn Leu Asp Lys
Ala Lys 180 185 190 Ala Ala Val Asp Gln Ile Asn Gln Tyr Leu Pro Lys
Val Thr Asp Ala 195 200 205 210 Phe Lys Thr Glu Leu Thr Glu Val Ala
Lys Lys Ala Leu Asp Ala Asp 215 220 225 Glu Ala Ala Leu Thr Pro Lys
Val Glu Ser Val Ser Ala Ile Asn Thr 230 235 240 Gln Asn Lys Ala Val
Glu Leu Thr Ala Val Pro Val Asn Gly Thr Leu 245 250 255 Lys Leu Gln
Leu Ser Ala Ala Ala Asn Glu Asp Thr Val Asn Val Asn 260 265 270 Thr
Val Arg Ile Tyr Lys Val Asp Gly Asn Ile Pro Phe Ala Leu Asn 275 280
285 290 Thr Ala Asp Val Ser Leu Ser Thr Asp Gly Lys Thr Ile Thr Val
Asp 295 300 305 Ala Ser Thr Pro Phe Glu Asn Asn Thr Glu Tyr Lys Val
Val Val Lys 310 315 320 Gly Ile Lys Asp Lys Asn Gly Lys Glu Phe Lys
Glu Asp Ala Phe Thr 325 330 335 Phe Lys Leu Arg Asn Asp Ala Val Val
Thr Gln Val Phe Gly Thr Asn 340 345 350 Val Thr Asn Asn Thr Ser Val
Asn Leu Ala Ala Gly Thr Phe Asp Thr 355 360 365 370 Asp Asp Thr Leu
Thr Val Val Phe Asp Lys Leu Leu Ala Pro Glu Thr 375 380 385 Val Asn
Ser Ser Asn Val Thr Ile Thr Asp Val Glu Thr Gly Lys Arg 390 395 400
Ile Pro Val Ile Ala Ser Thr Ser Gly Ser Thr Ile Thr Ile Thr Leu
405
410 415 Lys Glu Ala Leu Val Thr Gly Lys Gln Tyr Lys Leu Ala Ile Asn
Asn 420 425 430 Val Lys Thr Leu Thr Gly Tyr Asn Ala Glu Ala Tyr Glu
Leu Val Phe 435 440 445 450 Thr Ala Asn Ala Ser Ala Pro Thr Val Ala
Thr Ala Pro Thr Thr Leu 455 460 465 Gly Gly Thr Thr Leu Ser Thr Gly
Ser Leu Thr Thr Asn Val Trp Gly 470 475 480 Lys Leu Ala Gly Gly Val
Asn Glu Ala Gly Thr Tyr Tyr Pro Gly Leu 485 490 495 Gln Phe Thr Thr
Thr Phe Ala Thr Lys Leu Asp Glu Ser Thr Leu Ala 500 505 510 Asp Asn
Phe Val Leu Val Glu Lys Glu Ser Gly Thr Val Val Ala Ser 515 520 525
530 Glu Leu Lys Tyr Asn Ala Asp Ala Lys Met Val Thr Leu Val Pro Lys
535 540 545 Ala Asp Leu Lys Glu Asn Thr Ile Tyr Gln Ile Lys Ile Lys
Lys Gly 550 555 560 Leu Lys Ser Asp Lys Gly Ile Glu Leu Gly Thr Val
Asn Glu Lys Thr 565 570 575 Tyr Glu Phe Lys Thr Gln Asp Leu Thr Ala
Pro Thr Val Ile Ser Val 580 585 590 Thr Ser Lys Asn Gly Asp Ala Gly
Leu Lys Val Thr Glu Ala Gln Glu 595 600 605 610 Phe Thr Val Lys Phe
Ser Glu Asn Leu Asn Thr Phe Asn Ala Thr Thr 615 620 625 Val Ser Gly
Ser Thr Ile Thr Tyr Gly Gln Val Ala Val Val Lys Ala 630 635 640 Gly
Ala Asn Leu Ser Ala Leu Thr Ala Ser Asp Ile Ile Pro Ala Ser 645 650
655 Val Glu Ala Val Thr Gly Gln Asp Gly Thr Tyr Lys Val Lys Val Ala
660 665 670 Ala Asn Gln Leu Glu Arg Asn Gln Gly Tyr Lys Leu Val Val
Phe Gly 675 680 685 690 Lys Gly Ala Thr Ala Pro Val Lys Asp Ala Ala
Asn Ala Asn Thr Leu 695 700 705 Ala Thr Asn Tyr Ile Tyr Thr Phe Thr
Thr Glu Gly Gln Asp Val Thr 710 715 720 Ala Pro Thr Val Thr Lys Val
Phe Lys Gly Asp Ser Leu Lys Asp Ala 725 730 735 Asp Ala Val Thr Thr
Leu Thr Asn Val Asp Ala Gly Gln Lys Phe Thr 740 745 750 Ile Gln Phe
Ser Glu Glu Leu Lys Thr Ser Ser Gly Ser Leu Val Gly 755 760 765 770
Gly Lys Val Thr Val Glu Lys Leu Thr Asn Asn Gly Trp Val Asp Ala 775
780 785 Gly Thr Gly Thr Thr Val Ser Val Ala Pro Lys Thr Asp Ala Asn
Gly 790 795 800 Lys Val Thr Ala Ala Val Val Thr Leu Thr Gly Leu Asp
Asn Asn Asp 805 810 815 Lys Asp Ala Lys Leu Arg Leu Val Val Asp Lys
Ser Ser Thr Asp Gly 820 825 830 Ile Ala Asp Val Ala Gly Asn Val Ile
Lys Glu Lys Asp Ile Leu Ile 835 840 845 850 Arg Tyr Asn Ser Trp Arg
His Thr Val Ala Ser Val Lys Ala Ala Ala 855 860 865 Asp Lys Asp Gly
Gln Asn Ala Ser Ala Ala Phe Pro Thr Ser Thr Ala 870 875 880 Ile Asp
Thr Thr Lys Ser Leu Leu Val Glu Phe Asn Glu Thr Asp Leu 885 890 895
Ala Glu Val Lys Pro Glu Asn Ile Val Val Lys Asp Ala Ala Gly Asn 900
905 910 Ala Val Ala Gly Thr Val Thr Ala Leu Asp Gly Ser Thr Asn Lys
Phe 915 920 925 930 Val Phe Thr Pro Ser Gln Glu Leu Lys Ala Gly Thr
Val Tyr Ser Val 935 940 945 Thr Ile Asp Gly Val Arg Asp Lys Val Gly
Asn Thr Ile Ser Lys Tyr 950 955 960 Ile Thr Ser Phe Lys Thr Val Ser
Ala Asn Pro Thr Leu Ser Ser Ile 965 970 975 Ser Ile Ala Asp Gly Ala
Val Asn Val Asp Arg Ser Lys Thr Ile Thr 980 985 990 Ile Glu Phe Ser
Asp Ser Val Pro Asn Pro Thr Ile Thr Leu Lys Lys 995 1000 1005 1010
Ala Asp Gly Thr Ser Phe Thr Asn Tyr Thr Leu Val Asn Val Asn Asn
1015 1020 1025 Glu Asn Lys Thr Tyr Lys Ile Val Phe His Lys Gly Val
Thr Leu Asp 1030 1035 1040 Glu Phe Thr Gln Tyr Glu Leu Ala Val Ser
Lys Asp Phe Gln Thr Gly 1045 1050 1055 Thr Asp Ile Asp Ser Lys Val
Thr Phe Ile Thr Gly Ser Val Ala Thr 1060 1065 1070 Asp Glu Val Lys
Pro Ala Leu Val Gly Val Gly Ser Trp Asn Gly Thr 1075 1080 1085 1090
Ser Tyr Thr Gln Asp Ala Ala Ala Thr Arg Leu Arg Ser Val Ala Asp
1095 1100 1105 Phe Val Ala Glu Pro Val Ala Leu Gln Phe Ser Glu Gly
Ile Asp Leu 1110 1115 1120 Thr Asn Ala Thr Val Thr Val Thr Asn Ile
Thr Asp Asp Lys Thr Val 1125 1130 1135 Glu Val Ile Ser Lys Glu Ser
Val Asp Ala Asp His Asp Ala Gly Ala 1140 1145 1150 Thr Lys Glu Thr
Leu Val Ile Asn Thr Val Thr Pro Leu Val Leu Asp 1155 1160 1165 1170
Asn Ser Lys Thr Tyr Lys Ile Val Val Ser Gly Val Lys Asp Ala Ala
1175 1180 1185 Gly Asn Val Ala Asp Thr Ile Thr Phe Tyr Ile Lys 1190
1195 3 33 DNA Artificial Sequence Description of Artificial
Sequence synthetic primer 3 ttaatcgatt ctagatggat aggaaaaaag ctg 33
4 37 DNA Artificial Sequence Description of Artificial Sequence
synthetic primer 4 atacccgggg gtacggatcc gatacagatt tgagcaa 37 5
2766 DNA Bacillus stearothermophilus CDS (1)..(2763) sig_peptide
(1)..(93) mat_peptide (94)..(2763) 5 atg gct tat caa cct aag tct
ttt cgc aag ttt gtt gcg aca act gca 48 Met Ala Tyr Gln Pro Lys Ser
Phe Arg Lys Phe Val Ala Thr Thr Ala -30 -25 -20 aca gct gcc att gta
gca tct gcg gta gct cct gta gta tct gca gca 96 Thr Ala Ala Ile Val
Ala Ser Ala Val Ala Pro Val Val Ser Ala Ala -15 -10 -5 -1 1 agc ttc
aca gat gtt gcg ccg caa tat aaa gat gcg atc gat ttc tta 144 Ser Phe
Thr Asp Val Ala Pro Gln Tyr Lys Asp Ala Ile Asp Phe Leu 5 10 15 gta
tca act ggt gca aca aaa ggt aaa aca gaa aca aaa ttc ggc gtt 192 Val
Ser Thr Gly Ala Thr Lys Gly Lys Thr Glu Thr Lys Phe Gly Val 20 25
30 tac gat gaa atc act cgt cta gat gcg gca gtt att ctt gca aga gta
240 Tyr Asp Glu Ile Thr Arg Leu Asp Ala Ala Val Ile Leu Ala Arg Val
35 40 45 tta aaa cta gac gtt gac aac gca aaa gac gca ggc ttc aca
gat gtg 288 Leu Lys Leu Asp Val Asp Asn Ala Lys Asp Ala Gly Phe Thr
Asp Val 50 55 60 65 cca aaa gac cgt gca aaa tac gtc aac gcg ctt gta
gaa gct ggc gta 336 Pro Lys Asp Arg Ala Lys Tyr Val Asn Ala Leu Val
Glu Ala Gly Val 70 75 80 tta aac ggt aaa gca cct ggc aaa ttt ggt
gca tac gac cca tta act 384 Leu Asn Gly Lys Ala Pro Gly Lys Phe Gly
Ala Tyr Asp Pro Leu Thr 85 90 95 cgc gtt gaa atg gca aaa atc atc
gcg aac cgt tac aaa tta aaa gct 432 Arg Val Glu Met Ala Lys Ile Ile
Ala Asn Arg Tyr Lys Leu Lys Ala 100 105 110 gac gat gta aaa ctt cca
ttc act gat gta aac gat aca tgg gca cca 480 Asp Asp Val Lys Leu Pro
Phe Thr Asp Val Asn Asp Thr Trp Ala Pro 115 120 125 tac gta aaa gcg
ctt tat aaa tac gaa gta acc aaa agg tta aaa cac 528 Tyr Val Lys Ala
Leu Tyr Lys Tyr Glu Val Thr Lys Arg Leu Lys His 130 135 140 145 caa
caa gct tcg gtg cat acc aaa aac atc act ctg cgt gac ttt gcg 576 Gln
Gln Ala Ser Val His Thr Lys Asn Ile Thr Leu Arg Asp Phe Ala 150 155
160 caa ttt gta tat aga gcg gtg aat att aat gca gtg cca gaa ata gtt
624 Gln Phe Val Tyr Arg Ala Val Asn Ile Asn Ala Val Pro Glu Ile Val
165 170 175 gaa gta act gcg gtt aat tcg act aca gtg aaa gta aca ttc
aat acg 672 Glu Val Thr Ala Val Asn Ser Thr Thr Val Lys Val Thr Phe
Asn Thr 180 185 190 caa att gct gat gtt gat ttc aca aat ttt gct atc
gat aac ggt tta 720 Gln Ile Ala Asp Val Asp Phe Thr Asn Phe Ala Ile
Asp Asn Gly Leu 195 200 205 act gtt act aaa gca act ctt tct cgt gat
aaa aaa tcc gta gag gtt 768 Thr Val Thr Lys Ala Thr Leu Ser Arg Asp
Lys Lys Ser Val Glu Val 210 215 220 225 gtg gta aat aaa ccg ttt act
cgt aat cag gaa tat aca att aca gcg 816 Val Val Asn Lys Pro Phe Thr
Arg Asn Gln Glu Tyr Thr Ile Thr Ala 230 235 240 aca ggc att aaa aat
tta aaa ggc gag acc gct aag gaa tta act ggt 864 Thr Gly Ile Lys Asn
Leu Lys Gly Glu Thr Ala Lys Glu Leu Thr Gly 245 250 255 aag ttt gtt
tgg tct gtt caa gat gcg gta act gtt gca cta aat aat 912 Lys Phe Val
Trp Ser Val Gln Asp Ala Val Thr Val Ala Leu Asn Asn 260 265 270 agt
tcg ctt aaa gtt gga gag gaa tct ggt tta act gta aaa gat cag 960 Ser
Ser Leu Lys Val Gly Glu Glu Ser Gly Leu Thr Val Lys Asp Gln 275 280
285 gat ggc aaa gat gtt gta ggt gct aaa gta gaa ctt act tct tct aat
1008 Asp Gly Lys Asp Val Val Gly Ala Lys Val Glu Leu Thr Ser Ser
Asn 290 295 300 305 act aat att gtt gta gtt tca agt ggc gaa gta tca
gta tct gct gct 1056 Thr Asn Ile Val Val Val Ser Ser Gly Glu Val
Ser Val Ser Ala Ala 310 315 320 aaa gtt aca gct gta aaa ccg gga aca
gct gat gtt act gca aaa gtt 1104 Lys Val Thr Ala Val Lys Pro Gly
Thr Ala Asp Val Thr Ala Lys Val 325 330 335 aca tta cca gat ggt gtt
gta cta aca aat aca ttt aaa gtg aca gtt 1152 Thr Leu Pro Asp Gly
Val Val Leu Thr Asn Thr Phe Lys Val Thr Val 340 345 350 aca gaa gtg
cct gtt caa gtc caa aat caa gga ttt act tta gtt gat 1200 Thr Glu
Val Pro Val Gln Val Gln Asn Gln Gly Phe Thr Leu Val Asp 355 360 365
aat ctt tct aat gct cca cag aat aca gtt gca ttt aac aaa gct gag
1248 Asn Leu Ser Asn Ala Pro Gln Asn Thr Val Ala Phe Asn Lys Ala
Glu 370 375 380 385 aaa gta act tca atg ttt gct gga gaa act aaa aca
gtt gca atg tat 1296 Lys Val Thr Ser Met Phe Ala Gly Glu Thr Lys
Thr Val Ala Met Tyr 390 395 400 gat act aaa aac ggt gat cct gaa act
aaa cct gtt gat ttc aaa gat 1344 Asp Thr Lys Asn Gly Asp Pro Glu
Thr Lys Pro Val Asp Phe Lys Asp 405 410 415 gca act gta cgt tca tta
aat cca att att gca aca gct gct att aat 1392 Ala Thr Val Arg Ser
Leu Asn Pro Ile Ile Ala Thr Ala Ala Ile Asn 420 425 430 ggt agt gag
ctc ctt gtc aca gct aat gct ggc caa tct gga aaa gct 1440 Gly Ser
Glu Leu Leu Val Thr Ala Asn Ala Gly Gln Ser Gly Lys Ala 435 440 445
tca ttt gaa gta aca tta aaa gat aat aca aaa aga aca ttt aca gtt
1488 Ser Phe Glu Val Thr Leu Lys Asp Asn Thr Lys Arg Thr Phe Thr
Val 450 455 460 465 gat gta aaa aaa gac cct gta tta caa gat ata aaa
gta gat gca act 1536 Asp Val Lys Lys Asp Pro Val Leu Gln Asp Ile
Lys Val Asp Ala Thr 470 475 480 tct gtt aaa ctt tcc gat gaa gct gtt
ggc ggc ggg gaa gtt gaa gga 1584 Ser Val Lys Leu Ser Asp Glu Ala
Val Gly Gly Gly Glu Val Glu Gly 485 490 495 gtt aac caa aaa acg att
aaa gta agt gca gtt gac caa tac ggt aaa 1632 Val Asn Gln Lys Thr
Ile Lys Val Ser Ala Val Asp Gln Tyr Gly Lys 500 505 510 gaa att aaa
ttt ggt aca aaa ggt aaa gtt act gtt aca act aat aca 1680 Glu Ile
Lys Phe Gly Thr Lys Gly Lys Val Thr Val Thr Thr Asn Thr 515 520 525
gaa gga cta gtt att aaa aat gta aat agc gat aat aca att gac ttt
1728 Glu Gly Leu Val Ile Lys Asn Val Asn Ser Asp Asn Thr Ile Asp
Phe 530 535 540 545 gat agc ggc aat agt gca act gac caa ttt gtt gtc
gtt gca aca aaa 1776 Asp Ser Gly Asn Ser Ala Thr Asp Gln Phe Val
Val Val Ala Thr Lys 550 555 560 gac aaa att gtc aat ggt aaa gta gaa
gtt aaa tat ttc aaa aat gct 1824 Asp Lys Ile Val Asn Gly Lys Val
Glu Val Lys Tyr Phe Lys Asn Ala 565 570 575 agt gac aca aca cca act
tca act aaa aca att act gtt aat gta gta 1872 Ser Asp Thr Thr Pro
Thr Ser Thr Lys Thr Ile Thr Val Asn Val Val 580 585 590 aat gta aaa
gct gac gct aca cca gta gga tta gat att gta gca cct 1920 Asn Val
Lys Ala Asp Ala Thr Pro Val Gly Leu Asp Ile Val Ala Pro 595 600 605
tct aaa att gat gta aat gct cca aac act gct tct act gca gat gtt
1968 Ser Lys Ile Asp Val Asn Ala Pro Asn Thr Ala Ser Thr Ala Asp
Val 610 615 620 625 gat ttt ata aat ttc gaa agt gtt gag att tac aca
ctc gat tca aat 2016 Asp Phe Ile Asn Phe Glu Ser Val Glu Ile Tyr
Thr Leu Asp Ser Asn 630 635 640 ggt aga cgt caa aaa aaa gtt act cca
act gca act aca ctt gta ggt 2064 Gly Arg Arg Gln Lys Lys Val Thr
Pro Thr Ala Thr Thr Leu Val Gly 645 650 655 aca aaa aaa aaa aaa aaa
gtt aat ggg aat gta tta caa ttc aag ggg 2112 Thr Lys Lys Lys Lys
Lys Val Asn Gly Asn Val Leu Gln Phe Lys Gly 660 665 670 aac gaa gaa
tta acg cta tca act tct tct agt aca gga aac gta gat 2160 Asn Glu
Glu Leu Thr Leu Ser Thr Ser Ser Ser Thr Gly Asn Val Asp 675 680 685
gga aca gca gaa gga atg aca aaa cgt att cca ggg aaa tat atc aac
2208 Gly Thr Ala Glu Gly Met Thr Lys Arg Ile Pro Gly Lys Tyr Ile
Asn 690 695 700 705 tct gca agt gta cct gcc agt gca aca gta gca aca
agt cct gtt act 2256 Ser Ala Ser Val Pro Ala Ser Ala Thr Val Ala
Thr Ser Pro Val Thr 710 715 720 gta aag ctt aat tca agt gat aat gat
tta aca ttt gaa gaa tta ata 2304 Val Lys Leu Asn Ser Ser Asp Asn
Asp Leu Thr Phe Glu Glu Leu Ile 725 730 735 ttc ggt gta att gac cct
aca caa tta gtc aaa gat gaa gac atc aac 2352 Phe Gly Val Ile Asp
Pro Thr Gln Leu Val Lys Asp Glu Asp Ile Asn 740 745 750 gaa ttt att
gca gtt tca aaa gcg gct aaa aat gat gga tat ttg tat 2400 Glu Phe
Ile Ala Val Ser Lys Ala Ala Lys Asn Asp Gly Tyr Leu Tyr 755 760 765
aat aaa ccg ctt gta acg gtt aaa gat gca tca gga aaa gtt att cca
2448 Asn Lys Pro Leu Val Thr Val Lys Asp Ala Ser Gly Lys Val Ile
Pro 770 775 780 785 aca ggt gca aat gtt tac ggt cta aat cat gat gca
act aac gga aac 2496 Thr Gly Ala Asn Val Tyr Gly Leu Asn His Asp
Ala Thr Asn Gly Asn 790 795 800 att tgg ttt gat gag gaa caa gct ggc
tta gct aaa aaa ttt agt gat 2544 Ile Trp Phe Asp Glu Glu Gln Ala
Gly Leu Ala Lys Lys Phe Ser Asp 805 810 815 gta cat ttt gat gtt gat
ttt tca tta act aac gtt gta aaa act ggt 2592 Val His Phe Asp Val
Asp Phe Ser Leu Thr Asn Val Val Lys Thr Gly 820 825 830 agc ggt aca
gtt tct tca tcg cca tca tta tct gac gca att caa ctt 2640 Ser Gly
Thr Val Ser Ser Ser Pro Ser Leu Ser Asp Ala Ile Gln Leu 835 840 845
act aat tca ggc gat gca gta tcg ttt aca tta gtt atc aaa tca att
2688 Thr Asn Ser Gly Asp Ala Val Ser Phe Thr Leu Val Ile Lys Ser
Ile 850 855 860 865 tat gtt aaa ggc gca gat aaa gat gat aat aac tta
ctt gca gcc cct 2736 Tyr Val Lys Gly Ala Asp Lys Asp Asp Asn Asn
Leu Leu Ala Ala Pro 870 875 880 gtt tct gtc aat gtg act gtg aca aaa
taa 2766 Val Ser Val Asn Val Thr Val Thr Lys 885 890 6 921 PRT
Bacillus stearothermophilus 6 Met Ala Tyr Gln Pro Lys Ser Phe Arg
Lys Phe Val Ala Thr Thr Ala -30 -25 -20 Thr Ala Ala Ile Val Ala Ser
Ala Val Ala Pro Val Val Ser Ala Ala -15 -10 -5 -1 1 Ser Phe Thr Asp
Val Ala Pro Gln Tyr Lys Asp Ala Ile Asp Phe Leu 5 10 15 Val Ser Thr
Gly Ala Thr Lys Gly Lys Thr Glu Thr Lys Phe Gly Val 20 25 30 Tyr
Asp Glu Ile Thr Arg Leu Asp Ala Ala Val Ile Leu Ala Arg Val 35 40
45 Leu Lys Leu Asp Val Asp Asn Ala Lys Asp Ala Gly Phe Thr Asp Val
50 55 60 65 Pro Lys Asp Arg Ala Lys Tyr Val Asn Ala Leu Val Glu Ala
Gly Val 70 75
80 Leu Asn Gly Lys Ala Pro Gly Lys Phe Gly Ala Tyr Asp Pro Leu Thr
85 90 95 Arg Val Glu Met Ala Lys Ile Ile Ala Asn Arg Tyr Lys Leu
Lys Ala 100 105 110 Asp Asp Val Lys Leu Pro Phe Thr Asp Val Asn Asp
Thr Trp Ala Pro 115 120 125 Tyr Val Lys Ala Leu Tyr Lys Tyr Glu Val
Thr Lys Arg Leu Lys His 130 135 140 145 Gln Gln Ala Ser Val His Thr
Lys Asn Ile Thr Leu Arg Asp Phe Ala 150 155 160 Gln Phe Val Tyr Arg
Ala Val Asn Ile Asn Ala Val Pro Glu Ile Val 165 170 175 Glu Val Thr
Ala Val Asn Ser Thr Thr Val Lys Val Thr Phe Asn Thr 180 185 190 Gln
Ile Ala Asp Val Asp Phe Thr Asn Phe Ala Ile Asp Asn Gly Leu 195 200
205 Thr Val Thr Lys Ala Thr Leu Ser Arg Asp Lys Lys Ser Val Glu Val
210 215 220 225 Val Val Asn Lys Pro Phe Thr Arg Asn Gln Glu Tyr Thr
Ile Thr Ala 230 235 240 Thr Gly Ile Lys Asn Leu Lys Gly Glu Thr Ala
Lys Glu Leu Thr Gly 245 250 255 Lys Phe Val Trp Ser Val Gln Asp Ala
Val Thr Val Ala Leu Asn Asn 260 265 270 Ser Ser Leu Lys Val Gly Glu
Glu Ser Gly Leu Thr Val Lys Asp Gln 275 280 285 Asp Gly Lys Asp Val
Val Gly Ala Lys Val Glu Leu Thr Ser Ser Asn 290 295 300 305 Thr Asn
Ile Val Val Val Ser Ser Gly Glu Val Ser Val Ser Ala Ala 310 315 320
Lys Val Thr Ala Val Lys Pro Gly Thr Ala Asp Val Thr Ala Lys Val 325
330 335 Thr Leu Pro Asp Gly Val Val Leu Thr Asn Thr Phe Lys Val Thr
Val 340 345 350 Thr Glu Val Pro Val Gln Val Gln Asn Gln Gly Phe Thr
Leu Val Asp 355 360 365 Asn Leu Ser Asn Ala Pro Gln Asn Thr Val Ala
Phe Asn Lys Ala Glu 370 375 380 385 Lys Val Thr Ser Met Phe Ala Gly
Glu Thr Lys Thr Val Ala Met Tyr 390 395 400 Asp Thr Lys Asn Gly Asp
Pro Glu Thr Lys Pro Val Asp Phe Lys Asp 405 410 415 Ala Thr Val Arg
Ser Leu Asn Pro Ile Ile Ala Thr Ala Ala Ile Asn 420 425 430 Gly Ser
Glu Leu Leu Val Thr Ala Asn Ala Gly Gln Ser Gly Lys Ala 435 440 445
Ser Phe Glu Val Thr Leu Lys Asp Asn Thr Lys Arg Thr Phe Thr Val 450
455 460 465 Asp Val Lys Lys Asp Pro Val Leu Gln Asp Ile Lys Val Asp
Ala Thr 470 475 480 Ser Val Lys Leu Ser Asp Glu Ala Val Gly Gly Gly
Glu Val Glu Gly 485 490 495 Val Asn Gln Lys Thr Ile Lys Val Ser Ala
Val Asp Gln Tyr Gly Lys 500 505 510 Glu Ile Lys Phe Gly Thr Lys Gly
Lys Val Thr Val Thr Thr Asn Thr 515 520 525 Glu Gly Leu Val Ile Lys
Asn Val Asn Ser Asp Asn Thr Ile Asp Phe 530 535 540 545 Asp Ser Gly
Asn Ser Ala Thr Asp Gln Phe Val Val Val Ala Thr Lys 550 555 560 Asp
Lys Ile Val Asn Gly Lys Val Glu Val Lys Tyr Phe Lys Asn Ala 565 570
575 Ser Asp Thr Thr Pro Thr Ser Thr Lys Thr Ile Thr Val Asn Val Val
580 585 590 Asn Val Lys Ala Asp Ala Thr Pro Val Gly Leu Asp Ile Val
Ala Pro 595 600 605 Ser Lys Ile Asp Val Asn Ala Pro Asn Thr Ala Ser
Thr Ala Asp Val 610 615 620 625 Asp Phe Ile Asn Phe Glu Ser Val Glu
Ile Tyr Thr Leu Asp Ser Asn 630 635 640 Gly Arg Arg Gln Lys Lys Val
Thr Pro Thr Ala Thr Thr Leu Val Gly 645 650 655 Thr Lys Lys Lys Lys
Lys Val Asn Gly Asn Val Leu Gln Phe Lys Gly 660 665 670 Asn Glu Glu
Leu Thr Leu Ser Thr Ser Ser Ser Thr Gly Asn Val Asp 675 680 685 Gly
Thr Ala Glu Gly Met Thr Lys Arg Ile Pro Gly Lys Tyr Ile Asn 690 695
700 705 Ser Ala Ser Val Pro Ala Ser Ala Thr Val Ala Thr Ser Pro Val
Thr 710 715 720 Val Lys Leu Asn Ser Ser Asp Asn Asp Leu Thr Phe Glu
Glu Leu Ile 725 730 735 Phe Gly Val Ile Asp Pro Thr Gln Leu Val Lys
Asp Glu Asp Ile Asn 740 745 750 Glu Phe Ile Ala Val Ser Lys Ala Ala
Lys Asn Asp Gly Tyr Leu Tyr 755 760 765 Asn Lys Pro Leu Val Thr Val
Lys Asp Ala Ser Gly Lys Val Ile Pro 770 775 780 785 Thr Gly Ala Asn
Val Tyr Gly Leu Asn His Asp Ala Thr Asn Gly Asn 790 795 800 Ile Trp
Phe Asp Glu Glu Gln Ala Gly Leu Ala Lys Lys Phe Ser Asp 805 810 815
Val His Phe Asp Val Asp Phe Ser Leu Thr Asn Val Val Lys Thr Gly 820
825 830 Ser Gly Thr Val Ser Ser Ser Pro Ser Leu Ser Asp Ala Ile Gln
Leu 835 840 845 Thr Asn Ser Gly Asp Ala Val Ser Phe Thr Leu Val Ile
Lys Ser Ile 850 855 860 865 Tyr Val Lys Gly Ala Asp Lys Asp Asp Asn
Asn Leu Leu Ala Ala Pro 870 875 880 Val Ser Val Asn Val Thr Val Thr
Lys 885 890 7 498 DNA Unknown Organism Description of Unknown
Organism streptavidin gene 7 cccatggacc cgtccaagga ctccaaagct
caggtttctg cagccgaagc tggtatcact 60 ggcacctggt ataaccaact
ggggtcgact ttcattgtga ccgctggtgc ggacggagct 120 ctgactggca
cctacgaatc tgcggttggt aacgcagaat cccgctacgt actgactggc 180
cgttatgact ctgcacctgc caccgatggc tctggtaccg ctctgggctg gactgtggct
240 tggaaaaaca actatcgtaa tgcgcacagc gccactacgt ggtctggcca
atacgttggc 300 ggtgctgagg ctcgtatcaa cactcagtgg ctgttaacat
ccggcactac cgaagcgaat 360 gcatggaaat cgacactagt aggtcatgac
acctttacca aagttaagcc ttctgctgct 420 agcattgatg ctgccaagaa
agcaggcgta aacaacggta accctctaga cgctgttcag 480 caataataag gatccggg
498 8 29 DNA Artificial Sequence Description of Artificial Sequence
synthetic primer 8 ttcatcgtaa acgccgaatt ttgtttctg 29 9 26 DNA
Artificial Sequence Description of Artificial Sequence synthetic
primer 9 agggaaatat atcaactctg caagtg 26 10 49 DNA Bacillus
stearothermophilus 10 gaattcatcg atgtcgacca aggaggtcta gatggatccg
gccaagctt 49
* * * * *