Source: http://www.docstoc.com/docs/97711610/L-cysteine-producing-Bacterium-And-A-Method-For-Producing-L-cysteine---Patent-8008048
Timestamp: 2013-12-22 08:23:26
Document Index: 548420941

Matched Legal Cases: ['Application No.\n2008', 'Application No.\n20050112731', 'Application No. 20050112731', 'Application No. 20050112731', 'Application No. 20050112731', 'Application No. 20050112731', 'Application No. 20050112731', 'Application No.2008', 'Application No.20050112731']

L-cysteine-producing Bacterium And A Method For Producing L-cysteine - Patent 8008048
United States Patent: 8008048
8,008,048
L-cysteine-producing bacterium and a method for producing L-cysteine
The present invention provides a bacterium belonging to the family
Enterobacteriaceae which has L-cysteine-producing ability and has been
modified to decrease the activity of the protein encoded by the yhaM
gene. This bacterium is cultured in a medium, and L-cysteine, L-cystine,
their derivatives, or a mixture thereof is collected from the medium.
Nonaka; Gen (Kawasaki, JP), Takumi; Kazuhiro (Kawasaki, JP)
12/397,666
2008-056362
435/113  ; 435/252.3; 435/252.33; 435/440; 435/69.1; 530/350; 536/23.1
C12P 13/12&amp;nbsp(20060101); C12N 15/00&amp;nbsp(20060101); C07K 14/00&amp;nbsp(20060101); C12N 1/21&amp;nbsp(20060101); C07H 21/00&amp;nbsp(20060101); C12P 21/00&amp;nbsp(20060101)
435/113,69.1,320.1,252.3,252.33 536/23.2
5618716
5856148
5972663
Winterhalter et al.
6218168
Leinfelder et al.
7348037
2003/0077766
2003/0186393
2004/0038352
2005/0009162
2005/0112731
2005/0124049
Ziyatdinov et al.
2005/0221453
2008/0076163
2008/0193470
Masignani et al.
2386539
11-155571
2002-233384
2003-169668
2005-245311
2005-287333
WO01/27307
Branden et al., Introduction to Protein Structure, Garland Publishing Inc., New York, p. 247, 1991. cited by examiner
Zhou et al., Cell Mol Life Sci 63(19-20):2260-2290, 2006. cited by examiner
Kozak, M., Gene 234:187-208, 1999. cited by examiner
Sousa et al., Microbiology 148(Pt5):1291-1303, 2002. cited by examiner
Awano, N., et al., &quot;Effect of cysteine desulfhydrase gene disruption on L-cysteine overproduction in Escherichia coil,&quot; Appl. Microbiol. Biotechnol. 2003;62:239-243. cited by other
Awano, N., et al., &quot;Identification and Functional Analysis of Escherichia coli Cysteine Desulfhydrases,&quot; Appl. Environmen. Microbiol. 2005;71(7):4149-4152. cited by other
Da.beta.ler, T., et al., &quot;Identification of a major facilitator protein from Escherichia coli involved in efflux of metabolites of the cysteine pathway,&quot; Molecular Microbiol. 2000;36(5):1101-1112. cited by other
Dominy, J. E., et al., &quot;Identification and Characterization of Bacterial Cysteine Dioxygenases: a New Route of Cysteine Degradation for Eubacteria,&quot; J. Bacteriol. 2006;188(15):5561-5569. cited by other
EcoCyc (BioCyc Home Page, Summary of Escherichia coli, Strain K-12, version 11.6, E. coli K-12 Gene: yhaM, http://biocyc.org/ECOLI/NEW-IMAGE?type=GENE&amp;object=G7622). cited by other
Flatley, J., et al., &quot;Transcriptional Responses of Escherichia coli to D-Nitrosoglutathione under Defined Chemostat Conditions Reveal Major Changes in Methionine Biosynthesis,&quot; J. Biol. Chem. 2005;280(11):10065-10072. cited by other
Pae, K. M., et al., &quot;Kinetic Properties of a L-Cysteine Desulfhydrase-Deficient Mutant in the Enzymatic Formation of L-Cysteine from D,L-ATC,&quot; Biotechnol. Lett. 1992;14(12):1143-1148. cited by other
Soutourina, J., et al., &quot;Role of D-Cysteine Desulfhydrase in the Adaptation of Escherichia coli to D-Cysteine,&quot; J. Biol. Chem. 2001;276(44):40864-40872. cited by other
Tchong, S-I., et al., &quot;L-Cysteine Desulfidase: An [4Fe-4S] Enzyme Isolated from Methanocaldococcus jannaschii That Catalyzes the Breakdown of L-Cysteine into Pyruvate, Ammonia, and Sulfide,&quot; Biochem. 2005;44(5):1659-1670. cited by other
Wada, M., et al., &quot;Purification, characterization and identification of cysteine desulfhydrase of Corynebacterium glutamicum, and its relationship to cysteine production,&quot; FEMS Microbiol. Lett. 2002;217:103-107. cited by other
Zdych, E., et al., &quot;MalY of Escherichia coli Is an Enzyme with the Activity of .beta.C-S Lyase (Cystathionase),&quot; J. Bacteriol. 1995;177(17):5035-5039. cited by other
Database UniProt [Online], Nov. 1, 1995, &quot;RecName: Full=UPF0597 protein yhaM;&quot; retrieved from EBI accession No. UNIPROT: P42626, Database accession No. P42626. cited by other
Denk, D., et al., &quot;L-Cysteine Biosynthesis in Escherichia coli: Nucleotide Sequence and Expression of the Serine Acetyltransferase (cysE) Gene from the Wild-type and a Cysteine-excreting Mutant,&quot; J. Gen. Microbiol. 1987;133:515-525. cited by other
Takagi, H., et al., &quot;Overproduction of L-Cysteine and L-Cystine by expression of genes for feedback inhibition-insensitive serine acetyltransferase from Arabidopsis thaliana in Escherichia coli,&quot; FEMS Microbiol. Lett. 1999;179:453-459. cited by
Wada, M., et al., &quot;Metabolic pathways and biotechnological production of L-cysteine,&quot; Appl. Microbiol. Biotechnol. 2006;73:48-54. cited by other
European Search Report for European Patent App. No. 09003106.3 (Nov. 11, 2009). cited by other
Flatley, J., et al., &quot;Transcriptional Responses of Escherichia coli to S-Nitrosoglutathione under Defined Chemostat Conditions Reveal Major Changes in Methionine Biosynthesis,&quot; J. Biol. Chem. 2005;280(11):10065-10072. cited by other.
Primary Examiner: Ramirez; Delia
Attorney, Agent or Firm: Cermak; Shelly Guest
1.  A method for producing a compound selected from the group consisting of L-cysteine, L-cystine, a derivative thereof, and combinations thereof, which comprises culturing a
bacterium belonging to the family Enterobacteriaceae in a medium and collecting the compound from the medium, wherein said bacterium has L-cysteine-producing ability and has been modified to decrease the expression of the protein encoded by the yhaM gene
as compared to the corresponding unmodified bacterium, wherein said expression is decreased by disrupting the yhaM gene, and wherein, prior to modification, the protein is selected from the group consisting of: (A) a protein comprising the amino acid
sequence of SEQ ID NO: 2, and (B) a protein comprising the amino acid sequence of SEQ ID NO: 2 but which includes substitutions, deletions, insertions, or additions of one to 10 amino acid residues, and wherein L-cysteine-producing ability of the
bacterium is improved as compared to the corresponding unmodified bacterium.
2.  The method according to claim 1, wherein the derivative of L-cysteine is a thiazolidine derivative.
3.  The method according to claim 1, wherein, prior to the modification, the yhaM gene is selected from the group consisting of: (a) a DNA comprising the nucleotide sequence of SEQ ID NO: 1, and (b) a DNA which is able to hybridize with a
polynucleotide having a sequence complementary to the nucleotide sequence of SEQ ID NO: 1, or a probe which is prepared from the nucleotide sequence, under stringent conditions comprising washing at 60.degree.  C., 0.1.times.SSC, 0.1% SDS.
4.  The method according to claim 1, wherein serine acetyltransferase has been mutated so that feedback inhibition by L-cysteine is attenuated in said bacterium.
5.  The method according to claim 1, wherein said bacterium is an Escherichia bacterium.
6.  The method according to claim 5, wherein said bacterium is Escherichia coli.  Description
This application claims priority under 35 U.S.C.  .sctn.119 to Japanese Patent Application No.
2008-056362, filed on Mar.  6, 2008, which is incorporated in its entirety by reference.  The Sequence Listing in electronic format filed herewith is also hereby incorporated by reference in its entirety (File Name: US-385_Seq_List; File Size: 72 KB;
Date Created: Mar.  4, 2009).
The present invention relates to a method for producing L-cysteine or related substances.  Specifically, the present invention relates to a bacterium suitable for the production of L-cysteine or related substances and a method for producing
L-cysteine or related substances utilizing such a bacterium.  L-cysteine and L-cysteine-related substances are used in the fields of drugs, cosmetics, and foods.
2.  Brief Description of the Related Art
L-cysteine is conventionally obtained by extraction from keratin-containing substances such as hairs, horns, and feathers, or by conversion of DL-2-aminothiazoline-4-carboxylic acid using a microbial enzyme.  L-cysteine has also been produced on
a large scale by using an immobilized enzyme method and a novel enzyme.  Furthermore, it has also been attempted to produce L-cysteine by fermentation utilizing a microorganism.
Microorganisms which are able to produce L-cysteine are known.  For example, a coryneform bacterium with increased intracellular serine acetyltransferase activity produces cysteine (Japanese Patent Laid-open (Kokai) No. 2002-233384).
L-cysteine-producing ability can also be increased by incorporating serine acetyltransferase which has been mutated to attenuate feedback inhibition by L-cysteine (Japanese Patent Laid-open No. 11-155571, U.S.  Patent Published Application No.
20050112731, U.S.  Pat.  No. 6,218,168).
Furthermore, L-cysteine-producing ability in a microorganism can be enhanced by suppressing the L-cysteine decomposition system.  Examples of such microorganisms include coryneform bacteria or Escherichia bacteria in which the activity of
cystathionine-.beta.-lyase (U.S.  Patent Published Application No. 20050112731), tryptophanase (Japanese Patent Laid-open No. 2003-169668), or O-acetylserine sulfhydrylase B (Japanese Patent Laid-open No. 2005-245311) is attenuated or deleted.
Furthermore, it is known that the ydeD gene which encodes the YdeD protein participates in secretion of the metabolic products of the cysteine pathway (Dabler et al., Mol. Microbiol., 36, 1101-1112 (2000)).  Furthermore, techniques of enhancing
L-cysteine-producing ability by increasing expression of the mar-locus, emr-locus, acr-locus, cmr-locus, mex-gene, bmr-gene, or qacA-gene, are also known.  These loci and/or genes encode proteins which cause secretion of toxic substances from cells (U.S. Pat.  No. 5,972,663).  emrAB, emrKY, yojIH, acrEF, bcr, and cusA are further examples (Japanese Patent Laid-open No. 2005-287333).
An Escherichia coli has been reported which produces L-cysteine, and which has increased activity of the positive transcriptional control factor of the cysteine regulon encoded by the cysB gene (International Patent Publication WO01/27307).
yhaM is registered at the database EcoCyc (BioCyc Home Page, Summary of Escherichia coli, Strain K-12, version 11.6, E. coli K-12 Gene: yhaM, biocyc.org/ECOLI/NEW-IMAGE?type=GENE&amp;object=G7622) as a gene of unknown function, and it&#39;s relation
with L-cysteine production is also unknown.
The present invention provides a novel technique for improving bacterial L-cysteine-producing ability, and thereby provides an L-cysteine-producing bacterium, as well as a method for producing L-cysteine, L-cystine, their derivatives, or a
mixture of these by using such a bacterium.
L-cysteine-producing ability of a bacterium is enhanced by modifying the bacterium so that the activity of the protein encoded by the yhaM gene is decreased.
It is an aspect of the present invention to provide a bacterium belonging to the family Enterobacteriaceae, which has L-cysteine-producing ability and has been modified to decrease the activity of the protein encoded by the yhaM gene as compared
to the unmodified bacterium.
It is a further aspect of the present invention to provide the aforementioned bacterium, wherein the activity of the protein is decreased by attenuating expression of the yhaM gene or by disrupting the gene.
It is a further aspect of the present invention to provide the aforementioned bacterium, wherein the protein is selected from the group consisting of:
(A) a protein comprising the amino acid sequence of SEQ ID NO: 2, and
(B) a protein comprising the amino acid sequence of SEQ ID NO: 2, but which includes substitutions, deletions, insertions or additions of one or several amino acid residues, and wherein L-cysteine-producing ability of the bacterium is improved
as compared to an unmodified bacterium.
It is a further aspect of the present invention to provide the aforementioned bacterium, wherein the yhaM gene is selected from the group consisting of:
(a) a DNA comprising the nucleotide sequence of SEQ ID NO: 1, and
(b) a DNA which is able to hybridize with a sequence complementary to the nucleotide sequence of SEQ ID NO: 1 or a probe which is prepared from the nucleotide sequence, under stringent conditions, and wherein L-cysteine-producing ability of the
bacterium is improved as compared to an unmodified bacterium.
It is a further aspect of the present invention to provide the aforementioned bacterium, in which serine acetyltransferase has been mutated so that feedback inhibition by L-cysteine is attenuated.
It is a further aspect of the present invention to provide the aforementioned bacterium, which is an Escherichia bacterium.
It is a further aspect of the present invention to provide the aforementioned bacterium, which is Escherichia coli.
It is a further aspect of the present invention to provide a method for producing an L-amino acid selected from the group consisting of L-cysteine, L-cystine, a derivative thereof, and combinations thereof, which comprises culturing the
aforementioned bacterium in a medium and collecting the L-amino acid from the medium.
It is a further aspect of the present invention to provide the aforementioned method, wherein the derivative of L-cysteine is a thiazolidine derivative.
According to the present invention, L-cysteine-producing ability of bacteria can be improved.  Furthermore, according to the present invention, L-cysteine, L-cystine, their derivatives, or combinations thereof can be efficiently produced.
FIG. 1 shows the construction of the pMIV-5JS plasmid.
FIG. 2 shows the construction of pM12.
FIG. 3 shows the construction of the pM12-ter(thr) plasmid.  The sequences in the drawing are shown as SEQ ID NOS: 11 and 12.
FIG. 4 shows the construction of the IntJS cassette.
FIG. 5 shows the growth of a yhaM-deficient strain and a yhaM-enhanced strain in the presence of L-cysteine.
&amp;lt;1&amp;gt; Bacterium
The bacterium belongs to the family Enterobacteriaceae, and is able to produce L-cysteine.  Furthermore, the bacterium has been modified to decrease the activity of the protein encoded by the yhaM gene.  The &quot;ability to produce L-cysteine&quot; or
the &quot;L-cysteine-producing ability&quot; means an ability of the bacterium to produce L-cysteine and cause accumulation of L-cysteine in a medium or the bacterial cells in such an amount that the L-cysteine can be collected from the medium or cells when the
bacterium is cultured in the medium.  A bacterium having L-cysteine-producing ability means a bacterium which can produce and cause accumulation of a larger amount of L-cysteine as compared with a wild-type, parent, or unmodified strain, and preferably a
bacterium which can produce and cause accumulation of L-cysteine in a medium in an amount of 0.05 g/L or more, more preferably 0.1 g/L or more, particularly preferably 0.2 g/L or more.
The L-cysteine produced by the bacterium may change into L-cystine in the medium by the formation of a disulfide bond.  Furthermore, as described later, S-sulfocysteine may be generated by the reaction of L-cysteine and thiosulfuric acid in the
medium (Szczepkowski T. W., Nature, vol. 182 (1958)).  Furthermore, the L-cysteine generated in bacterial cells may be condensed with a ketone, aldehyde, or, for example, pyruvic acid, which is present in the cells, to produce a thiazolidine derivative
via an hemithioketal intermediate (refer to Japanese Patent No. 2992010).  This thiazolidine derivative and hemithioketal may be present as an equilibrated mixture.  Therefore, the L-cysteine-producing ability is not limited to the ability to accumulate
only L-cysteine in the medium or cells, but also includes the ability to accumulate L-cystine or its derivative such as S-sulfocysteine, a thiazolidine derivative, or a hemithioketal, or a mixture thereof in the medium.
The bacterium having L-cysteine-producing ability may inherently have the ability to produce L-cysteine, or it may be imparted by modifying a microorganism such as those described below by mutagenesis or a recombinant DNA technique.  Unless
specially mentioned, the term L-cysteine refers to the reduced-type L-cysteine, L-cystine, derivatives such as those mentioned above, or a mixture thereof.
The bacterium is not particularly limited so long as the bacterium belongs to the family Enterobacteriaceae and has L-cysteine-producing ability.  Such bacteria include those of the genera Escherichia, Enterobacter, Pantoea, Klebsiella,
Serratia, Erwinia, Salmonella, and Morganella.  Specifically, those classified into the family Enterobacteriaceae according to the taxonomy used in the NCBI (National Center for Biotechnology Information) database
www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?id=91347) can be used.  As the parent strain of the family Enterobacteriaceae which can be used to perform the modification, it is desirable to use, especially, a bacterium of the genus Escherichia,
Enterobacter, Pantoea, Erwinia, or Klebsiella.
Although the Escherichia bacteria are not particularly limited, specifically, those described in the work of Neidhardt et al. (Backmann B. J., 1996, Derivations and Genotypes of some mutant derivatives of Escherichia coli K-12, p. 2460-2488,
Table 1, In F. D. Neidhardt (ed.), Escherichia coli and Salmonella Cellular and Molecular Biology/Second Edition, American Society for Microbiology Press, Washington, D.C.) can be used.  Escherichia coli is preferable.  Examples of Escherichia coli
include Escherichia coli W3110 (ATCC 27325), Escherichia coli MG1655 (ATCC 47076), and so forth, and include those derived from the prototype wild-type strain, K12 strain.
These strains are available from, for example, the American Type Culture Collection (Address: 12301 Parklawn Drive, Rockville, Md.  20852, P.O.  Box 1549, Manassas, Va.  20108, United States of America).  That is, registration numbers are given
to each of the strains, and the strains can be ordered by using these registration numbers (refer to www.atcc.org/).  The registration numbers of the strains are listed in the catalogue of the American Type Culture Collection.
Examples of the Enterobacter bacteria include Enterobacter agglomerans, Enterobacter aerogenes and so forth, and examples of the Pantoea bacteria include Pantoea ananatis.  Some strains of Enterobacter agglomerans were recently reclassified into
Pantoea agglomerans, Pantoea ananatis, or Pantoea stewartii on the basis of the nucleotide sequence analysis of 16S rRNA etc. A bacterium belonging to either Enterobacter or Pantoea may be used so long as it is classified as the family
In particular, Pantoea bacteria, Erwinia bacteria, and Enterobacter bacteria are classified as .gamma.-proteobacteria, and they are taxonomically very close to one another (J. Gen.  Appl.  Microbiol., 1997, 43, 355-361; Int.  J. Syst.
Bacteriol., 1997, 43, 1061-1067).  In recent years, some bacteria belonging to the genus Enterobacter were reclassified as Pantoea agglomerans, Pantoea dispersa, or the like, on the basis of DNA-DNA hybridization experiments etc. (International Journal
of Systematic Bacteriology, July 1989, 39:337-345).  Furthermore, some bacteria belonging to the genus Erwinia were reclassified as Pantoea ananas or Pantoea stewartii (refer to Int.  J. Syst.  Bacteriol., 1993, 43:162-173).
Examples of the Enterobacter bacteria include, but are not limited to, Enterobacter agglomerans, Enterobacter aerogenes, and so forth.  Specifically, the strains exemplified in European Patent Publication No. 952221 can be used.
A typical strain of the genus Enterobacter is the Enterobacter agglomeranses ATCC 12287 strain.
Typical strains of the Pantoea bacteria include, but are not limited to, Pantoea ananatis, Pantoea stewartii, Pantoea agglomerans, and Pantoea citrea.
Specific examples of Pantoea ananatis include the Pantoea ananatis AJ13355 strain and SC17 strain.  The SC17 strain was selected as a low phlegm-producing mutant strain from the AJ13355 strain (FERM BP-6614), which was isolated from soil in
Iwata-shi, Shizuoka-ken, Japan for it&#39;s ability to proliferate in a low pH medium containing L-glutamic acid and a carbon source (U.S.  Pat.  No. 6,596,517).
The Pantoea ananatis AJ13355 strain was deposited at the National Institute of Bioscience and Human-Technology, Agency of Industrial Science and Technology, Ministry of International Trade and Industry (currently, the National Institute of
Advanced Industrial Science and Technology, International Patent Organism Depositary, Address: Tsukuba Central 6, 1-1, Higashi 1-Chome, Tsukuba-shi, Ibaraki-ken, 305-8566, Japan) on Feb.  19, 1998 and assigned an accession number of FERM P-16644.  It was
then converted to an international deposit under the provisions of Budapest Treaty on Jan.  11, 1999 and assigned an accession number of FERM BP-6614.  This strain was identified as Enterobacter agglomerans when it was isolated and deposited as the
Enterobacter agglomerans AJ13355 strain.  However, it was recently reclassified as Pantoea ananatis on the basis of nucleotide sequencing of 16S rRNA and so forth.
Examples of the Erwinia bacteria include, but are not limited to, Erwinia amylovora and Erwinia carotovora, and examples of the Klebsiella bacteria include Klebsiella planticola.
Hereinafter, methods for imparting L-cysteine-producing ability to bacteria belonging to Enterobacteriaceae, or methods for enhancing L-cysteine-producing ability of such bacteria, are described.
To impart the ability to produce L-cysteine, methods conventionally employed in the breeding of coryneform bacteria or bacteria of the genus Escherichia (see &quot;Amino Acid Fermentation&quot;, Gakkai Shuppan Center (Ltd.), 1st Edition, published May 30,
1986, pp.  77-100) can be used.  Such methods include by acquiring the properties of an auxotrophic mutant, an analogue-resistant strain, or a metabolic regulation mutant, or by constructing a recombinant strain so that it overexpresses an L-cysteine
biosynthesis enzyme.  Here, in the breeding of an L-cysteine-producing bacteria, one or more of the above described properties may be imparted.  The expression of L-cysteine biosynthesis enzyme(s) can be enhanced alone or in combinations of two or more.
Furthermore, imparting properties such as an auxotrophic mutation, analogue resistance, or metabolic regulation mutation may be combined with the methods of enhancing the biosynthesis enzymes.
An auxotrophic mutant strain, L-cysteine analogue-resistant strain, or metabolic regulation mutant strain with the ability to produce L-cysteine can be obtained by subjecting a parent, wild-type, or unmodified strain to conventional
mutatagenesis, such as exposure to X-rays or UV irradiation, or by treating with a mutagen such as N-methyl-N&#39;-nitro-N-nitrosoguanidine, etc., then selecting those which exhibit autotrophy, analogue resistance, or a metabolic regulation mutation and
which also have the ability to produce L-cysteine.
Specific examples of L-cysteine-producing bacteria include, but are not limited to, E. coli JM15 transformed with multiple kinds of cysE gene alleles encoding serine acetyltransferase resistant to feedback inhibition (U.S.  Pat.  No. 6,218,168),
E. coli W3110 in which a gene encoding a protein responsible for excretion of cytotoxic substances is overexpressed (U.S.  Pat.  No. 5,972,663) an E. coli strain having decreased cysteine desulfhydrase activity (Japanese Patent Laid-open No. 11-155571),
and E. coli W3110 with increased activity of the positive transcriptional control factor of the cysteine regulon encoded by the cysB gene (WO01/27307).
The following proteins are known to have the cysteine desulfhydrase activity of E. coli: cystathionine-.beta.-lyase (metC product, Japanese Patent Laid-open No. 11-155571, Chandra et al., Biochemistry, 21 (1982) 3064-3069), tryptophanase (tnaA
product, Japanese Patent Laid-open No. 2003-169668, Austin Newton et al., J. Biol.  Chem., 240 (1965) 1211-1218)), O-acetylserine sulfhydrylase B (cysM gene product, Japanese Patent Laid-open No. 2005-245311), and the malY gene product (Japanese Patent
Laid-open No. 2005-245311).  By decreasing the activities of these proteins, L-cysteine-producing ability is improved.
The L-cysteine-producing bacterium preferably has a SAT which has been mutated to be resistant to feedback inhibition.  The following mutations in SAT are known to induce resistance to feedback inhibition and are derived from Escherichia coli:
when the methionine residue at position 256 is replaced with a glutamate residue (Japanese Patent Laid-open No. 11-155571), when the methionine residue at position 256 is replaced with an isoleucine residue (Denk, D. and Boeck, A., J. General Microbiol.,
133, 515-525 (1987)), a mutation in the region from the amino acid residue at position 97 to the amino acid residue at position 273 or a deletion of the C-terminus region from the amino acid residue at position 227 (International Patent Publication
WO97/15673, U.S.  Pat.  No. 6,218,168), when the amino acid sequence corresponding to positions 89 to 96 of the wild-type SAT contains one or more mutations (U.S.  Patent Published Application No. 20050112731(A1)), and so forth.  In the cysE5 gene which
encodes the mutant SAT described in the examples, the Val residue and the Asp residue at positions 95 and 96 of the wild-type SAT are replaced with an Arg residue and Pro residue, respectively.
The SAT gene is not limited to the gene of Escherichia coli, but can be any gene encoring a protein having the SAT activity.  An SAT isozyme of Arabidopsis thaliana and desensitized to feedback inhibition by L-cysteine is known, and the gene
encoding this SAT can also be used (FEMS Microbiol.  Lett., 179 (1999) 453-459).
If a gene encoding a mutant SAT is introduced into a bacterium, L-cysteine-producing ability is imparted to the bacterium.  To introduce a mutant SAT gene into a bacterium, various vectors which are typically used for protein expression can be
used.  Examples of such vectors include pUC19, pUC18, pHSG299, pHSG399, pHSG398, RSF1010, pBR322, pACYC184, pMW219, and so forth.
In order to introduce a recombinant vector containing a SAT gene into a bacterium, methods which are typically used to transform bacteria can be used, such as the method of D. A. Morrison (Methods in Enzymology, 68, 326 (1979)), treating
recipient cells with calcium chloride to increase permeability of the cells for DNA (Mandel, M. and Higa, A., J. Mol. Biol., 53, 159 (1970)), and a method based on electroporation.
Furthermore, the SAT activity can also be enhanced by increasing the copy number of the SAT gene.  The copy number of the SAT gene can be increased by introducing the SAT gene into a bacterium by using a vector such as those described above, or
by introducing multiple copies of the SAT gene onto the chromosomal DNA of a bacterium.  Multiple copies of the SAT gene are introduced by homologous recombination which targets a sequence present on the chromosomal DNA in multiple copies.  A repetitive
DNA or inverted repeat present at the end of a transposable element can be used as a sequence which is present on the chromosomal DNA in multiple copies.  Alternatively, as disclosed in Japanese Patent Laid-open No. 2-109985, multiple copies of the SAT
gene can be introduced into the chromosomal DNA by incorporating them into a transposon and transferring it.
The bacterium can be obtained by modifying a bacterium belonging to the family Enterobacteriaceae which has L-cysteine-producing ability, such as those described above, so that the activity of the protein encoded by yhaM (henceforth also
referred to as &quot;YhaM&quot;) is decreased.  Alternatively, after such modification that the activity of the YhaM protein is decreased, L-cysteine-producing ability may be imparted.
The yhaM gene is synonymous with ECK3099, b4470, and yhaN, and it has also been called b3109 or b3108.
The phrase &quot;decrease the activity of the protein encoded by the yhaM gene&quot; means that the activity of the YhaM protein encoded by the yhaM gene is decreased as compared to a non-modified strain, such as a wild-type strain or parent strain, and
also means the complete disappearance of the activity.
Modifications to decrease the activity of the YhaM protein are attained by, for example, reducing the expression of the yhaM gene.  Specifically, for example, intracellular activity of the protein can be reduced by deleting a part or all of the
coding region of the yhaM gene on the chromosome.  Furthermore, this gene forms an operon with the yhaO gene (database &quot;Regulon DB&quot;, regulondb.ccg.unam.mx/), and the activity of the YhaM protein can also be decreased by reducing the expression, for
example, by modifying an expression control sequence of the operon such as a promoter or the Shine-Dalgarno (SD) sequence.  Furthermore, the expression of the gene can also be reduced by modifying a non-translated region other than the expression control
sequence.  Furthermore, the entire gene as well as the sequences on both sides of the gene on the chromosome may be deleted.  Furthermore, mutations which cause an amino acid substitution (missense mutation), a stop codon (nonsense mutation), or a frame
shift mutation which adds or deletes one or two nucleotides into the coding region of the yhaM gene on the chromosome can be introduced (Journal of Biological Chemistry, 272:8611-8617 (1997); Proceedings of the National Academy of Sciences, USA, 95
5511-5515 (1998); Journal of Biological Chemistry, 266, 20833-20839 (1991)).  Furthermore, expression of the yhaM gene can also be reduced by modifying the coding region or a non-coding region of the yhaO gene.
Furthermore, modification can be caused by a conventional mutagenesis based on X-ray or ultraviolet irradiation or the use of a mutagen such as N-methyl-N&#39;-nitro-N-nitrosoguanidine, so long as the activity of the YhaM protein is decreased.
An expression control sequence can be modified for preferably one or more nucleotides, more preferably two or more nucleotides, particularly preferably three or more nucleotides.  When a coding region is deleted, the region to be deleted may be
an N-terminus region, an internal region, or a C-terminus region, or even the entire coding region, so long as the function of the YhaM protein is decreased or deleted.  Deletion of a longer region can usually more surely inactivate a gene.  Furthermore,
it is preferred that the deleted reading frames upstream and downstream of the region are not the same.
When another sequence is inserted into the coding region of the yhaM gene, the sequence may be inserted into any region of the gene, and insertion of a longer sequence can usually more surely inactivate the gene.  It is preferred that the
reading frames upstream and downstream of the insertion site are not the same.  The other sequence is not particularly limited so long as a sequence which decreases or deletes function of the encoded YhaM protein is chosen, and examples include a
transposon carrying an antibiotic resistance gene, a gene useful for L-cysteine production, and so forth.
The yhaM gene on the chromosome can be modified as described above by, for example, preparing a deletion-type version of the gene in which a partial sequence of the gene is deleted so that the deletion-type gene does not produce
normally-functioning YhaM proteins, and transforming a bacterium with a DNA containing the deletion-type gene to cause homologous recombination between the deletion-type gene and the native gene on the chromosome, which results in the substitution of the
deletion-type gene for the gene on the genome.  The protein encoded by the deletion-type gene has a conformation different from that of the wild-type enzyme protein, if it is even produced, and thus the function is reduced or deleted.
Such gene disruption based on gene substitution utilizing homologous recombination is known, and examples include Red-driven integration (Datsenko, K. A, and Wanner, B. L., Proc.  Natl.  Acad.  Sci.  USA, 97:6640-6645 (2000)), using a linear DNA
in Red driven integration in combination with an excision system derived from .lamda.  phage (Cho, E. H., Gumport, R. I., Gardner, J. F., J. Bacteriol., 184:5200-5203 (2002)), using a plasmid containing a temperature sensitive replication origin or a
plasmid capable of conjugative transfer, utilizing a suicide vector without a replication origin in a host (U.S.  Pat.  No. 6,303,383, Japanese Patent Laid-open No. 05-007491), and so forth.
Decrease of the expression of the yhaM gene can be confirmed by comparing the amount of mRNA transcribed from the gene with that in a wild-type strain or unmodified strain.  The expression amount can be confirmed by Northern hybridization,
RT-PCR (Sambrook, J., Fritsch, E. F., and Maniatis, T. 1989, Molecular Cloning A Laboratory Manual/Second Edition, Cold Spring Harbor Laboratory Press, New York.), and the like.
Decrease of the amount of YhaM protein can be confirmed by Western blotting using antibodies (Molecular cloning, Cold spring Harbor Laboratory Press, Cold Spring Harbor, USA, 2001).
The nucleotide sequence of the yhaM gene of Escherichia coli and the amino acid sequence encoded by this gene are shown in SEQ ID NOS: 1 and 2, respectively.
As a result of a domain search of the YhaM protein performed using the search program Pfam, 78 kinds of proteins were retrieved including those derived from or originating from bacteria of the genera Escherichia, Salmonella and Shigella whose
functions are unknown (DUF1063), and therefore it is evident that these proteins are widely conserved in bacteria.  Since differences may exist in the nucleotide sequence of the yhaM gene depending on species or strain to which a bacterium belongs, the
yhaM gene to be modified may be a variant of the nucleotide sequence of SEQ ID NO: 1.  Variants of the yhaM gene can be searched for with BLAST blast.genome.jp/) or the like by referring to the nucleotide sequence of SEQ ID NO: 1.  Furthermore, variants
of the yhaM gene include genes which can be amplified by PCR using a homologue of the gene, for example, a chromosome of a microorganism such as those of the family Enterobacteriaceae and coryneform bacteria as the template, and synthetic oligonucleotide
primers prepared on the basis of the nucleotide sequence of SEQ ID NO: 1.
As examples of yhaM gene homologues from bacteria other than Escherichia coli, nucleotide sequences of the yhaM gene of the following bacteria and amino acid sequences are shown in SEQ ID NOS: 20 to 31.  Accession numbers in the NCBI (National
Center for Biotechnology Information) database are shown in the parentheses (GenBank Identifier(gi)|RefSeq accession (ref)).
Shigella boydii Sb227 (accession: gi/82545369|ref|YP.sub.--409316.1)
Citrobacter koseri ATCC BAA-895 (accession: gi|157148682|ref|YP.sub.--001456001.1)
Salmonella typhimurium LT2 (accession: gi|16766537|ref|NP.sub.--462152.1)
Actinobacillus pleuropneumoniae serovar.  3 str.  JL03 (accession: gi|165977041|ref|YP.sub.--001652634.1)
Klebsiella pneumoniae subsp.  pneumoniae MGH 78578 (accession: gi|152972895|ref|YP.sub.--001338041.1|)
Vibrio fischeri ES114 (accession: gi|59711248|ref|YP.sub.--204024.1|)
The yhaM gene may also encode a protein having a sequence corresponding to the aforementioned amino acid sequence of the YhaM protein, but which includes substitutions, deletions, insertions, additions or the like of one or several amino acid
residues at one or several positions.
Although the number of the &quot;one or several&quot; amino acid residues may differ depending on their position in the three-dimensional structure or the types of amino acid residues of the proteins, it is preferably 1 to 20, more preferably 1 to 10,
particularly preferably 1 to 5.  These substitutions, deletions, insertions, or additions of one or several amino acids are preferably conservative mutations so that the function of the protein is maintained.  A conservative mutation is a mutation
wherein substitution takes place mutually among Phe, Trp and Tyr, if the substitution site is an aromatic amino acid; among Leu, Ile and Val, if the substitution site is a hydrophobic amino acid; between Gln and Asn, if it is a polar amino acid; among
Lys, Arg and His, if it is a basic amino acid; between Asp and Glu, if it is an acidic amino acid; and between Ser and Thr, if it is an amino acid having a hydroxyl group.  Typical examples of conservative mutations are conservative substitutions.
Specific examples of conservative substitutions include: substitution of Ser or Thr for Ala; substitution of Gln, His or Lys for Arg; substitution of Glu, Gln, Lys, His or Asp for Asn; substitution of Asn, Glu or Gln for Asp; substitution of Ser or Ala
for Cys; substitution of Asn, Glu, Lys, His, Asp or Arg for Gln; substitution of Gly, Asn, Gln, Lys or Asp for Glu; substitution of Pro for Gly; substitution of Asn, Lys, Gln, Arg or Tyr for His; substitution of Leu, Met, Val or Phe for Ile; substitution
of Ile, Met, Val or Phe for Leu; substitution of Asn, Glu, Gln, His or Arg for Lys; substitution of Ile, Leu, Val or Phe for Met; substitution of Trp, Tyr, Met, Ile or Leu for Phe; substitution of Thr or Ala for Ser; substitution of Ser or Ala for Thr;
substitution of Phe or Tyr for Trp; substitution of His, Phe or Trp for Tyr; and substitution of Met, Ile or Leu for Val.  The above-mentioned amino acid substitution, deletion, insertion, addition, inversion, etc., may be the result of a
naturally-occurring mutation or variation due to an individual difference, or a difference of species of a bacterium.
Furthermore, the gene having such a conservative mutation as mentioned above may be a gene encoding a protein showing a homology of 80% or more, preferably 90% or more, more preferably 95% or more, still more preferably 97% or more, further
still more preferably 98% or more, particularly preferably 99% or more, to the entire encoded amino acid sequence, and which has a function equivalent to that of a wild-type YhaM protein.  In the present specification, the term &quot;homology&quot; may mean
&quot;identity&quot;.
The yhaM gene may be a DNA which hybridizes with a probe prepared from known gene sequences, for example, the above described gene sequences or sequences complementary to the sequences under stringent conditions and which encodes a protein which
is a functional equivalent to the YhaM protein.
The term &quot;stringent conditions&quot; refers to conditions where a so-called specific hybrid is formed and a non-specific hybrid is not formed.  Examples thereof include conditions where DNAs having high homology, for example, at least 80%, preferably
90%, more preferably 95%, more preferably 97%, more preferably 98%, further preferably 99% homology, hybridize with each other and DNAs having homology less than the value do not hybridize with each other; and specifically include conditions
corresponding to a salt concentration and temperature of washing which are typical of Southern hybridization, e.g., washing at 60.degree.  C., 1.times.SSC, 0.1% SDS, preferably 60.degree.  C., 0.1.times.SSC, 0.1% SDS, more preferably 68.degree.  C.,
0.1.times.SSC, 0.1% SDS, once or preferably twice or three times.
The probe may be a partial sequence of the gene.  Such a probe can be prepared by PCR using oligonucleotides prepared based on the known nucleotide sequences of genes as primers, and a DNA fragment containing these sequences as the template.
When a DNA fragment of a length of about 300 bp is used as the probe, the conditions of washing after hybridization can be, for example, 50.degree.  C., 2.times.SSC, and 0.1% SDS.
The above descriptions about variants of genes and proteins are similarly applied to enzymes such as serine acetyltransferase and genes coding for them.
&amp;lt;2&amp;gt; Method for Producing L-Cysteine, L-Cystine, Derivatives Thereof, or Mixture Thereof
These compounds can be produced by culturing the bacterium obtained as described above in a medium, and collecting L-cysteine, L-cystine, derivatives thereof, or a mixture thereof from the medium.  Examples of a derivative of L-cysteine include
S-sulfocysteine, a thiazolidine derivative, a hemithioketal corresponding the thiazolidine derivative mentioned above, and so forth.
Examples of the medium used for the culture include ordinary media containing a carbon source, nitrogen source, sulfur source, inorganic ions, and other organic components as required.
As the carbon source, saccharides such as glucose, fructose, sucrose, molasses and starch hydrolysate, and organic acids such as fumaric acid, citric acid and succinic acid can be used.
As the nitrogen source, inorganic ammonium salts such as ammonium sulfate, ammonium chloride and ammonium phosphate, organic nitrogen such as soybean hydrolysate, ammonia gas, aqueous ammonia, and so forth can be used.
As the sulfur source, inorganic sulfur compounds, such as sulfates, sulfites, sulfides, hyposulfites, and thiosulfates can be used.
As organic trace amount nutrients, it is desirable to add required substances such as vitamin B.sub.1, yeast extract, and so forth in appropriate amounts.  Other than these, potassium phosphate, magnesium sulfate, iron ions, manganese ions, and
so forth are added in small amounts.
The culture is preferably performed under aerobic conditions for 30 to 90 hours.  The culture temperature is preferably controlled to be 25.degree.  C. to 37.degree.  C., and the pH is preferably controlled to be 5 to 8 during the culture.  To
adjust the pH, inorganic or organic acidic or alkaline substances, ammonia gas, and so forth can be used.  Collection of L-cysteine from the culture can be attained by, for example, any combination of known ion exchange resin methods, precipitation, and
other known methods.
L-cysteine obtained as described above can be used to produce L-cysteine derivatives.  The cysteine derivatives include methylcysteine, ethylcysteine, carbocysteine, sulfocysteine, acetylcysteine, and so forth.
Furthermore, when a thiazolidine derivative of L-cysteine is produced in the medium, L-cysteine can be produced by collecting the thiazolidine derivative from the medium to break the reaction equilibrium between the thiazolidine derivative and
L-cysteine so that L-cysteine is excessively produced.
Furthermore, when S-sulfocysteine is produced in the medium, it can be converted into L-cysteine by reduction with a reducing agent such as dithiothreitol.
Hereinafter, the present invention will be explained more specifically with reference to the following non-limiting examples.  In the following descriptions, cysteine means L-cysteine.
(1) Cloning of yhaM Gene from E. coli MG1655 Strain
By conducting PCR using the chromosomal DNA of E. coli MG1655 (ATCC No. 47076) as the template, and the primers ECOyhaM-F (CGCGGATCCAAGATGCCTGCCGAGAAGATTAACG, SEQ ID NO: 3) and ECOyhaM-R (CGCGGATCCGAGCGAGCTGGAAGCTATCG, SEQ ID NO: 4), a yhaM gene
fragment containing 300 bp upstream and 200 bp downstream from the yhaM gene was obtained.  Restriction enzyme BamHI sites were designed in the 5&#39; ends of these primers.  For PCR, Pyrobest polymerase (Takara) was used, and after a reaction at 94.degree.
C. for 5 minutes, a cycle of 98.degree.  C. for 5 seconds, 55.degree.  C. for 5 seconds and 72.degree.  C. for 2 minutes was repeated 30 times in the standard reaction composition described in the protocol of the polymerase to amplify the target
fragment.  This fragment was treated with BamHI and inserted into pSTV29 (Takara) at the BamHI site in the direction opposite to the direction of the lacZ gene on the vector, to obtain the pSTV-yhaM7 plasmid having a chloramphenicol resistance marker and
the cloned yhaM.  It was confirmed by sequencing that there was no PCR error.
Then, the amplified fragment was excised from pSTV-yhaM7 with BamHI, and inserted into pACYC177 (Nippon Gene) at the BamHI site in the same direction as that of the kanamycin resistance gene on the vector, resulting in pACYC-M1 with a kanamycin
resistant marker.  In this way, the plasmids having two different antibiotic resistance markers and cloned with the same yhaM region (both had the same p15A origin) were prepared.
(2) Construction of a yhaM-Enhanced Strain from E. coli MG1655 Strain (MG1655/pSTV-yhaM7)
E. coli MG1655 was transformed with the pSTV-yhaM7 plasmid constructed as described above to prepare the MG1655/pSTV-yhaM7 strain, which is yhaM-enhanced.  Furthermore, a control strain, which was transformed with an empty vector and called
MG1655/pSTV29, was also prepared.  The transformation of E. coli was performed by a conventional method based on electroporation, and selection of the transformants was performed on the LB agar medium (5 g/L of yeast extract, 10 g/L of tryptone, 10 g/L
of sodium chloride, 15 g/L of agar) containing an antibiotic corresponding to the antibiotic resistance marker of the plasmid (25 mg/L in the case of chloramphenicol, 20 mg/L in the case of kanamycin).
(3) Construction of a yhaM-Deficient Strain from E. coli MG1655 Strain (MG1655.DELTA.yhaM Strain)
Deletion of the yhaM gene was performed by the method called &quot;Red-driven integration&quot;, first developed by Datsenko and Wanner (Proc.  Natl.  Acad.  Sci.  USA, 2000, vol. 97, No. 12, pp.  6640-6645), and an excision system derived from .lamda.
phage (J. Bacteriol., 2002 Sep., 184 (18):5200-3, Interactions between integrase and excisionase in the phage lambda excisive nucleoprotein complex, Cho E H, Gumport R I, and Gardner J F).  According to the &quot;Red-driven integration&quot; method, using a PCR
product obtained using synthetic oligonucleotides in which a part of a target gene is designed on the 5&#39; side, and a part of an antibiotic resistance gene is designed on the 3&#39; side, respectively, as primers, a gene-disrupted strain can be constructed in
one step.  By further using the excision system derived from .lamda.  phage in combination, the antibiotic resistance gene incorporated into the gene-disrupted strain can be removed.  This method for deleting a gene of E. coli using the &quot;Red-driven
integration&quot; and the excision system derived from .lamda.  phage is described in detail in Japanese Patent Laid-open No. 2005-058227, WO2007/119880A1 and so forth.  A yhaM gene-deficient strain was also obtained by these same methods.
A DNA fragment having sequences homologous to both ends of the yhaM gene, and with an antibiotic resistance gene (kanamycin resistance gene (Km.sup.r)) inserted between them, was obtained by PCR.  As for the specific experimental methods and
materials, PCR was performed in the same manner as described in Japanese Patent Laid-open No. 2005-058227, except that DyhaM-FW (ATGTTTGATTCGACTTTAAATCCGTTATGGCAGCGTTACATCCTCGCCGTTGA AGCCTGCTTTTTTATACTAAGTTGGCA, SEQ ID NO: 5) and DyhaM-RV
(TTATCTGGCCTTGCTCGCCATAATCTCGATAATCTGCCGATCCGTTTGCTCGC TCAAGTTAGTATAAAAAAGCTGAACGA, SEQ ID NO: 6) were used as primers, and pMW118-(.lamda.  attL-Km.sup.r-.lamda.  attR) (WO2006/093322A2) was used as the template.
(4) Construction of a Plasmid Carrying an Inhibition-Desensitized Type SAT (Serine Acetyltransferase) Gene (pMIV-CysE5)
It is known that the pMIV-CysE5 plasmid carries the cysE5 gene encoding a mutant SAT which is desensitized to feedback inhibition (U.S.  Patent Published Application No. 20050112731(A1)).  A cysteine-producing bacterium which produces a marked
amount of cysteine can be prepared by introducing this plasmid into the bacterium (U.S.  Patent Published Application No. 20050112731(A1), U.S.  Pat.  No. 5,972,663 etc.).  The construction method of pMIV-CysE5 is described below.
The mutant allele E. coli cysE gene, cysE5 (U.S.  Patent Published Application No. 20050112731(A1)) was obtained by PCR using primers cysEplF (5&#39;-agc-tga-gtc-gac-atg-tcg-tgt-gaa-gaa-ctg-gaa-3&#39;, SEQ ID NO: 7), cysER
(5&#39;-agc-tga-tct-aga-ata-gat-gat-tac-atc-gca-tcc-3&#39;, SEQ ID NO: 8), and the template pMW-PompC-cysE5 (EP1650296A1).  A cycle of 94.degree.  C. for 0.5 minute was conducted, then cycles of 57.degree.  C. for 0.5 minute and 72.degree.  C. for 1 minute were
repeated 27 times, and then the reaction was maintained at 72.degree.  C. for 7 minutes.  The cysEplF primer was designed so as to bind with the start codon ATG of the E. coli cysE gene and a downstream sequence, and has a 6-mer SalI site at the 5&#39; end.
The cysER primer was designed so as to bind with the stop codon of the E. coli cysE gene and an upstream sequence, and has a 6-mer XbaI site at the 5&#39; end.  A DNA fragment of about 0.7 kb obtained by PCR was digested with SalI and XbaI, and the digestion
product was inserted into the pMIV-PompC plasmid which had been similarly digested with SalI and XbaI to construct pMIV-CysE5.
The pMIV-PompC plasmid described above was constructed as follows.  By conducting PCR using the genomic DNA of the E. coli MG1655 strain as the template, primers PrOMPCF (5&#39;-agc-tga-gtc-gac-aac-cct-ctg-tta-tat-gcc-ttt-a-3&#39;, SEQ ID NO: 9) and
PrOMPCR (5&#39;-agc-tga-gca-tgc-gag-tga-agg-ttt-tgt-ttt-gac-3&#39;, SEQ ID NO: 10), a DNA fragment containing about 0.3 kb of a promoter region of the ompC gene was obtained, and this fragment was inserted into the pMIV-5JS plasmid at the PaeI and SalI sites to
construct pMIV-PompC.  The plasmid pMIV-5JS was constructed by ligating the BamHI and HindIII sites designed beforehand at both ends of the intJS cassette (described later) with the BglII and HindIII sites of pM12-ter(thr) (described later) (FIG. 1).
The pM12-ter(thr) plasmid was constructed (FIG. 3) by inserting a double stranded DNA fragment (thrL terminator, designed to have HindIII and PstI sites at both ends) produced by annealing a synthetic oligonucleotide (aagcttaaca cagaaaaaag
cccgcacctg acagtgcggg cttttttttt cgaccactgc ag, SEQ ID NO: 11) and a complementary synthetic oligonucleotide (ttcgaattgt gtcttttttc gggcgtggac tgtcacgccc gaaaaaaaaa gctggtgacg tc, SEQ ID NO: 12) into the pM12 plasmid which contains the integration
cassette derived from Mu phage (EP1486570(A1), FIG. 2) at the HindIII and Mph1103I sites.  The IntJS cassette was constructed by the following procedures (a) to (g) (FIG. 4).
(a) By conducting PCR using an upstream primer (ccagatcttg aagcctgctt ttttatacta agttggc, SEQ ID NO: 13, designed to have a BglII site), a downstream primer (gaaatcaaat aatgatttta ttttg, SEQ ID NO: 14, phosphorylated), and the
pMW118-attL-tet-attR-ter_rrnB plasmid (WO2005/010175) as the template, a LattL fragment of 0.12 kbp was obtained.
(b) By conducting PCR using an upstream primer (ttacgccccg ccctgccact catcgc, SEQ ID NO: 15, phosphorylated), a downstream primer (gtcactgcag ctgatgtccg gcggtgcttt tgcc, SEQ ID NO: 16, designed to have PstI site), and the pACYC184 plasmid (New
England Biolabs) as the template, a Cm.sup.R fragment of 1.03 kbp was obtained.
(c) By conducting PCR using an upstream primer (cagctgcagt ctgttacagg tcactaatac c, SEQ ID NO: 17, designed to have a PstI site), a downstream primer (ccgagctccg ctcaagttag tataaaaaag ctgaacg, SEQ ID NO: 18, designed to have a SacI site), and
the pMW118-attL-tet-attR-ter_rrnB plasmid (WO2005/010175) as the template, a LattR fragment of 0.16 kbp was obtained.
(d) By ligation of the LattL and Cm.sup.R fragments, a LattL-Cm.sup.R fragment of 1.15 kbp was obtained.
(e) By ligation of the LattL-Cm.sup.R and LattR fragments digested with PstI, a LattL-CmR-LattR fragment of 1.31 kbp was obtained.
(f) By annealing a synthetic oligonucleotide (cccgagctcg gtacctcgcg aatgcatcta gatgggcccg tcgactgcag aggcctgcat gcaagcttcc, SEQ ID NO: 19) with its complementary strand, a double stranded DNA fragment of 70 bp containing a multi-cloning site
(MCS) was obtained.
(g) By ligation of the LattL-Cm.sup.R-LattR fragment and the double stranded DNA fragment containing a multi-cloning site (MCS), and digested both with SacI, an IntJS fragment of 1.38 kbp was obtained.
(5) Construction of an E. coli Strain Having Cysteine-Producing Ability and Enhanced yhaM (MG1655/pMIV-CysE5/pACYC-M1 Strain)
The pACYC-M1 plasmid containing the yhaM gene constructed as described above (kanamycin resistant) was introduced into MG1655 (MG1655/pACYC-M1), along with the inhibition-desensitized type SAT gene-carrying plasmid pMIV-CysE5 (chloramphenicol
resistant) to construct an E. coli strain having cysteine-producing ability and enhanced yhaM (MG1655/pMIV-CysE5/pACYC-M1 strain).  Furthermore, as a control strain, MG1655/pMIV-CysE5/pACYC177 strain was prepared, which was transformed with the empty
vector pACYC177 instead of pACYC-M1.
(6) Construction of an E. coli Strain with Cysteine-Producing Ability and Deficient in yhaM (MG1655.DELTA.yhaM/pMIV-CysE5 Strain).
The yhaM-deficient strain (MG1655.DELTA.yhaM), constructed as described above, was transformed with the pMIV-CysE5 plasmid to prepare a yhaM-deficient cysteine-producing bacterium, MG1655.DELTA.yhaM/pMIV-CysE5.  The MG1655/pMIV-CysE5 strain was
prepared as a control, which corresponded to the wild-type strain MG1655 transformed with pMIV-CysE5.
(7) Effect of the Deletion and Enhancement of yhaM on Cysteine Resistance in the E. coli MG1655 Strain
In order to investigate the influence of the yhaM gene on cysteine resistance, the yhaM-deficient strain MG1655.DELTA.yhaM, the yhaM-amplified strain MG1655/pSTV-yhaM, as well as their respective control strains (MG1655 and MG1655/pSTV29) were
each cultured in M9 minimal medium (Sambrook et al., Molecular Cloning, 3rd edition, 2001, Cold Spring Harbor Laboratory Press) which contained cysteine at different concentrations.  The difference in cysteine resistance was evaluated by determining
change in growth.  As the resistance to cysteine increased, the OD of the medium more quickly increased, and as the resistance to cysteine decreased, the OD of the medium increased more slowly.  The procedure of the experiment was as follows.  Each
strain was precultured overnight in M9 minimal medium containing 0.4% of glucose, but no cysteine (3-ml test tube, 37.degree.  C., shaking culture), and then inoculated into the main culture medium.  At the time of the inoculation, the OD of the
preculture was measured, and the amount inoculated was adjusted so that the main culture began with the same amount of cells.  The OD at the time of the start of the main culture was about 0.005.
The main culture was performed in 4 ml of M9 minimal medium containing cysteine at the following concentrations: 0 mM, 0.1 mM, and 0.2 mM, and 0.4% of glucose using an automatically OD measuring culture apparatus, BIO-PHOTORECORDER TN-1506
(ADVANTEC) and the L-shaped test tube for the apparatus.  The progress of the culture (growth curves) is shown in FIG. 5.  It was observed that as the concentration of cysteine increased, the OD increased more slowly.  However, the yhaM-enhanced strain
MG1655/pSTV-yhaM7 grew more quickly as compared to the control MG1655/pSTV29 strain, and it was found to be resistant to cysteine.  Furthermore, since the growth of the yhaM-deficient strain MG1655.DELTA.yhaM was slowed as compared to the control MG1655
strain when cysteine was added, it was found that the cysteine resistance thereof had decreased.
(8) Effect of Enhancing yhaM on Cysteine Production in Cysteine-Producing Bacterium
In order to investigate the effect of enhancing the yhaM gene on cysteine production, the cysteine-producing abilities of the cysteine-producing bacterium E. coli MG1655/pMIV-CysE5/pACYC-M1 in which yhaM was enhanced, and the control
MG1655/pMIV-CysE5/pACYC177 strain were compared.  For the culture, a cysteine production medium (composition: 15 g/L of ammonium sulfate, 1.5 g/L of potassium dihydrogenphosphate, 1 g/L of magnesium sulfate heptahydrate, 0.1 mg/L of thiamine
hydrochloride, 1.7 mg/L of ferrous sulfate heptahydrate, 0.15 mg/L of sodium molybdate dihydrate, 0.7 mg/L of cobalt chloride hexahydrate, 1.6 mg/L of manganese chloride tetrahydrate, 0.3 mg/L of zinc sulfate heptahydrate, 0.25 mg/L of copper sulfate
pentahydrate, 0.6 g/L of tryptone, 0.3 g/L of yeast extract, 0.6 g/L of sodium chloride, 20 g/L of calcium carbonate, 135 mg/L of L-histidine monohydrochloride monohydrate, 4 g/L of sodium thiosulfate, 2 mg/L of pyridoxine hydrochloride, 40 g/L of
glucose, 25 mg/L of chloramphenicol and 20 mg/L of kanamycin) was used.
The culture was performed according to the following procedures.  The MG1655/pMIV-CysE5/pACYC-M1 and the MG1655/pMIV-CysE5/pACYC177 strains were each applied and spread on LB agar medium containing chloramphenicol and kanamycin, and precultured
overnight at 37.degree.  C. The cells on about 7 cm on the plate were scraped with an inoculating loop of 10 .mu.l (NUNC Blue Loop), and inoculated into 2 ml of the cysteine production medium in a large test tube (internal diameter: 23 mm, length: 20
cm).  The amounts of the inoculated cells were adjusted so that the cell amounts at the time of the start of the culture are substantially the same.  The culture was performed at 32.degree.  C. with shaking.  For both strains, after it was confirmed that
glucose in the medium had been completely consumed, the culture was ended, and the amount of cysteine which had accumulated in the medium was quantified.  The quantification of cysteine was performed by the method described by Gaitonde, M. K. (Biochem.
J., 1967 Aug., 104(2):627-33).  The experiment was performed in hexaplicate for the both strains, and averages and standard deviations of the accumulated cysteine amounts are shown in Table 1.  As shown in Table 1, it was revealed that enhancing yhaM
caused a decrease in the accumulation of cysteine.
TABLE-US-00001 TABLE 1 Strain Gene type Cys (mg/L) MG1655/pMIV-CysE5/pACYC177 Vector 64 .+-.  28 MG1655/pMIV-CysE5/pACYC-M1 yhaM (plasmid) 12 .+-.  6
(9) Effect of a Deficiency of yhaM on Cysteine-Producing Ability in Cysteine-Producing Bacterium
The cysteine-producing abilities of the yhaM-deficient cysteine-producing bacterium MG1655.DELTA.yhaM/pMIV-CysE5, prepared as described above, and the control MG1655/pMIV-CysE5 strain were compared.  For the culture, the cysteine production
medium composition was the same as that used in (8) except that kanamycin was not present.
The culture was performed according to the following procedures.  The MG1655.DELTA.yhaM/pMIV-CysE5 and the MG1655/pMIV-CysE5 strains were each applied and spread on LB agar medium containing chloramphenicol, and precultured overnight at
37.degree.  C. Then, the cells on about 7 cm on the plate were scraped with an inoculating loop of 10 .mu.l (NUNC Blue Loop), and inoculated into 2 ml of the cysteine production medium in a large test tube (internal diameter: 23 mm, length: 20 cm).  The
amounts of inoculated cells were adjusted so that the cell amounts at the time of the start of the culture are substantially the same.  The culture was performed at 32.degree.  C. with shaking.  After about 15 to 17 hours, it was confirmed that
substantially all the glucose in the medium had been consumed (it was confirmed that 95% or more of the total glucose had been consumed), then the culture was ended, and the amount of cysteine which had accumulated in the medium was quantified.  The
quantification of cysteine was performed by the method described by Gaitonde, M. K. (Biochem.  J., 1967 Aug., 104(2):627-33).  The experiment was performed in octaplicate for the yhaM-deficient strain and in tetraplicate for the control strain, and
averages and standard deviations of the produced cysteine amounts observed in the experiments are shown in Table 2.  As shown in Table 2, it was revealed that the deficiency of yhaM caused an increase in the ability of the bacterium to produce cysteine.
TABLE-US-00002 TABLE 2 Strain Gene type Cys (mg/L) MG1655/pMIV-CysE5 Vector 65 .+-.  4 MG1655.DELTA.yhaM/pMIV-CysE5 .DELTA.yhaM 287 .+-.  61
SEQ ID NO: 1: Nucleotide sequence of E. coli yhaM gene
SEQ ID NO: 2: Amino acid sequence of E. coli YhaM
SEQ ID NOS: 3 to 19: PCR primers
SEQ ID NO: 20: Nucleotide sequence of Shigella boydii yhaM gene
SEQ ID NO: 21: Amino acid sequence of Shigella boydii YhaM
SEQ ID NO: 22: Nucleotide sequence of Citrobacter koseri yhaM gene
SEQ ID NO: 23: Amino acid sequence of Citrobacter koseri YhaM
SEQ ID NO: 24: Nucleotide sequence of Salmonella typhimurium yhaM gene
SEQ ID NO: 25: Amino acid sequence of Salmonella typhimurium YhaM
SEQ ID NO: 26: Nucleotide sequence of Actinobacillus pleuropneumoniae yhaM gene
SEQ ID NO: 27: Amino acid sequence of Actinobacillus pleuropneumoniae YhaM
SEQ ID NO: 28: Nucleotide sequence of Klebsiella pneumoniae yhaM gene
SEQ ID NO: 29: Amino acid sequence of Klebsiella pneumoniae YhaM
SEQ ID NO: 30: Nucleotide sequence of Vibrio fischeri yhaM gene
SEQ ID NO: 31: Amino acid sequence of Vibrio fischeri YhaM
While the invention has been described in detail with reference to exemplary embodiments thereof, it will be apparent to one skilled in the art that various changes can be made, and equivalents employed, without departing from the scope of the
invention.  Each of the aforementioned documents is incorporated by reference herein in its entirety.
3NAEscherichia coliCDS(g ttt gat tcg act tta aat ccg tta tgg cag cgt tac atc ctc gcc 48Met Phe Asp
Ser Thr Leu Asn Pro Leu Trp Gln Arg Tyr Ile Leu Alaag gag gaa gta aaa ccg gcg ctg gga tgt act gaa ccg att tca 96Val Gln Glu Glu Val Lys Pro Ala Leu Gly Cys Thr Glu Pro Ile Ser 2ctg gcg ctg gcg gcg gcg gtt gct gcg gca gaa ctg gaa ggt
ccg gtt Ala Leu Ala Ala Ala Val Ala Ala Ala Glu Leu Glu Gly Pro Val 35 4 cgt gta gaa gcc tgg gtt tcg cca aat ctg atg aag aac ggt ctg Arg Val Glu Ala Trp Val Ser Pro Asn Leu Met Lys Asn Gly Leu 5ggc gtc acc gtt ccc ggc acg gga
atg gtg ggg ctg ccg att gcg gcg 24l Thr Val Pro Gly Thr Gly Met Val Gly Leu Pro Ile Ala Ala65 7gcg ctg ggg gcg tta ggt gga aat gcc aac gcc ggg ctg gaa gtg ctg 288Ala Leu Gly Ala Leu Gly Gly Asn Ala Asn Ala Gly Leu Glu Val Leu 85 9
gac gca aca gcg cag gca att gcc gat gcc aaa gca ctg ctg gcg 336Lys Asp Ala Thr Ala Gln Ala Ile Ala Asp Ala Lys Ala Leu Leu Ala  ggg aaa gtc tcc gtt aag atc cag gaa cct tgc gat gaa atc ctc 384Ala Gly Lys Val Ser Val Lys Ile Gln Glu Pro Cys
Asp Glu Ile Leu  tca cgc gcc aaa gtc tgg aac ggt gag aag tgg gcg tgt gtc acc 432Phe Ser Arg Ala Lys Val Trp Asn Gly Glu Lys Trp Ala Cys Val Thr  gtc ggc ggg cat acc aac att gtg cat atc gag acg cac gat ggt 48l Gly Gly
His Thr Asn Ile Val His Ile Glu Thr His Asp Gly gtg gtg ttt acc cag cag gcg tgt gtg gca gag ggc gag caa gag tct 528Val Val Phe Thr Gln Gln Ala Cys Val Ala Glu Gly Glu Gln Glu Ser  ctg acg gtg ctt tcc aga acg acg ctg gct gag
atc ctg aag ttc 576Pro Leu Thr Val Leu Ser Arg Thr Thr Leu Ala Glu Ile Leu Lys Phe  aat gaa gtc ccg ttt gcg gcg atc cgc ttt att ctc gat tcc gcg 624Val Asn Glu Val Pro Phe Ala Ala Ile Arg Phe Ile Leu Asp Ser Ala  2ta aat tgt
gcg tta tcg cag gaa ggt ttg agc ggt aag tgg ggg 672Lys Leu Asn Cys Ala Leu Ser Gln Glu Gly Leu Ser Gly Lys Trp Gly 222t att ggc gcg acg ctg gaa aaa cag tgc gag cgc ggt ttg ctg 72s Ile Gly Ala Thr Leu Glu Lys Gln Cys Glu Arg Gly Leu
Leu225 234a gat ctc tct tca tcc att gtg att cgt acc agc gcg gca tcc 768Ala Lys Asp Leu Ser Ser Ser Ile Val Ile Arg Thr Ser Ala Ala Ser 245 25t gcg cgt atg ggc ggc gct acg ctt ccg gct atg agt aac tcc ggc 8la Arg Met Gly Gly Ala
Thr Leu Pro Ala Met Ser Asn Ser Gly 267t aac cag ggg att acc gca aca atg cct gtg gtg gtg gta gca 864Ser Gly Asn Gln Gly Ile Thr Ala Thr Met Pro Val Val Val Val Ala 275 28a cac ttc gga gcg gat gat gaa cgg ctg gcg cgt gcg ctg atg ctt
9is Phe Gly Ala Asp Asp Glu Arg Leu Ala Arg Ala Leu Met Leu 29at ttg agc gca att tac atc cat aac cag tta ccg cgt ttg tct 96s Leu Ser Ala Ile Tyr Ile His Asn Gln Leu Pro Arg Leu Ser33cg ctg tgt gcc gca acg acc gca
gca atg ggg gcc gcc gcc ggg atg  Leu Cys Ala Ala Thr Thr Ala Ala Met Gly Ala Ala Ala Gly Met 325 33a tgg ctg gtg gat ggg cgt tat gaa acc atc tcg atg gcg atc agc  Trp Leu Val Asp Gly Arg Tyr Glu Thr Ile Ser Met Ala Ile Ser 345g atc ggc gat gtc agc ggc atg att tgc gat ggt gcg tcg aac  Met Ile Gly Asp Val Ser Gly Met Ile Cys Asp Gly Ala Ser Asn 355 36c tgc gcg atg aag gtt tcg acc agt gct tcg gct gcg tgg aaa gcg  Cys Ala Met Lys Val Ser Thr Ser Ala
Ser Ala Ala Trp Lys Ala 378a atg gcg ctg gat gat acc gcc gtg acc ggc aat gaa ggg att  Leu Met Ala Leu Asp Asp Thr Ala Val Thr Gly Asn Glu Gly Ile385 39cg cat gat gtt gag cag tcg att gcc aac ctg tgt gcg tta gca
Ala His Asp Val Glu Gln Ser Ile Ala Asn Leu Cys Ala Leu Ala 44at tcg atg cag caa acg gat cgg cag att atc gag att atg gcg  His Ser Met Gln Gln Thr Asp Arg Gln Ile Ile Glu Ile Met Ala 423g gcc aga taa  Lys Ala Arg
4352436PRTEscherichia coli 2Met Phe Asp Ser Thr Leu Asn Pro Leu Trp Gln Arg Tyr Ile Leu Alaln Glu Glu Val Lys Pro Ala Leu Gly Cys Thr Glu Pro Ile Ser 2Leu Ala Leu Ala Ala Ala Val Ala Ala Ala Glu Leu Glu Gly Pro Val 35 4 Arg
Val Glu Ala Trp Val Ser Pro Asn Leu Met Lys Asn Gly Leu 5Gly Val Thr Val Pro Gly Thr Gly Met Val Gly Leu Pro Ile Ala Ala65 7Ala Leu Gly Ala Leu Gly Gly Asn Ala Asn Ala Gly Leu Glu Val Leu 85 9 Asp Ala Thr Ala Gln Ala Ile Ala Asp Ala
Lys Ala Leu Leu Ala  Gly Lys Val Ser Val Lys Ile Gln Glu Pro Cys Asp Glu Ile Leu  Ser Arg Ala Lys Val Trp Asn Gly Glu Lys Trp Ala Cys Val Thr  Val Gly Gly His Thr Asn Ile Val His Ile Glu Thr His Asp Gly
Val Val Phe Thr Gln Gln Ala Cys Val Ala Glu Gly Glu Gln Glu Ser  Leu Thr Val Leu Ser Arg Thr Thr Leu Ala Glu Ile Leu Lys Phe  Asn Glu Val Pro Phe Ala Ala Ile Arg Phe Ile Leu Asp Ser Ala  2eu Asn Cys Ala
Leu Ser Gln Glu Gly Leu Ser Gly Lys Trp Gly 222s Ile Gly Ala Thr Leu Glu Lys Gln Cys Glu Arg Gly Leu Leu225 234s Asp Leu Ser Ser Ser Ile Val Ile Arg Thr Ser Ala Ala Ser 245 25p Ala Arg Met Gly Gly Ala Thr Leu Pro Ala
Met Ser Asn Ser Gly 267y Asn Gln Gly Ile Thr Ala Thr Met Pro Val Val Val Val Ala 275 28u His Phe Gly Ala Asp Asp Glu Arg Leu Ala Arg Ala Leu Met Leu 29is Leu Ser Ala Ile Tyr Ile His Asn Gln Leu Pro Arg Leu Ser33la Leu Cys Ala Ala Thr Thr Ala Ala Met Gly Ala Ala Ala Gly Met 325 33a Trp Leu Val Asp Gly Arg Tyr Glu Thr Ile Ser Met Ala Ile Ser 345t Ile Gly Asp Val Ser Gly Met Ile Cys Asp Gly Ala Ser Asn 355 36r Cys Ala Met Lys
Val Ser Thr Ser Ala Ser Ala Ala Trp Lys Ala 378u Met Ala Leu Asp Asp Thr Ala Val Thr Gly Asn Glu Gly Ile385 39la His Asp Val Glu Gln Ser Ile Ala Asn Leu Cys Ala Leu Ala 44is Ser Met Gln Gln Thr Asp Arg Gln Ile
Ile Glu Ile Met Ala 423s Ala Arg 435 334DNAArtificialprimer 3cgcggatcca agatgcctgc cgagaagatt aacg 34429DNAArtificialprimer 4cgcggatccg agcgagctgg aagctatcg 2958ificialprimer 5atgtttgatt cgactttaaa tccgttatgg cagcgttaca tcctcgccgt
tgaagcctgc 6atac taagttggca 8Artificialprimer 6ttatctggcc ttgctcgcca taatctcgat aatctgccga tccgtttgct cgctcaagtt 6aaaa agctgaacga 8Artificialprimer 7agctgagtcg acatgtcgtg tgaagaactg gaa 33833DNAArtificialprimer 8agctgatcta
gaatagatga ttacatcgca tcc 33934DNAArtificialprimer 9agctgagtcg acaaccctct gttatatgcc ttta 34Artificialprimer agcat gcgagtgaag gttttgtttt gac 33Artificialprimer taaca cagaaaaaag cccgcacctg acagtgcggg cttttttttt cgaccactgc 6262DNAArtificialprimer attgt gtcttttttc gggcgtggac tgtcacgccc gaaaaaaaaa gctggtgacg 6337DNAArtificialprimer tcttg aagcctgctt ttttatacta agttggc 37Artificialprimer caaat aatgatttta ttttg 25Artificialprimer
ccccg ccctgccact catcgc 26Artificialprimer tgcag ctgatgtccg gcggtgcttt tgcc 34Artificialprimer gcagt ctgttacagg tcactaatac c 3AArtificialprimer ctccg ctcaagttag tataaaaaag ctgaacg 37Artificialprimer
gctcg gtacctcgcg aatgcatcta gatgggcccg tcgactgcag aggcctgcat 6ttcc 7DNAShigella boydiiCDS(tg ttt gat tcg act tta aat ccg tta tgg cag cgt tac atc ctc gcc 48Met Phe Asp Ser Thr Leu Asn Pro Leu Trp Gln Arg Tyr Ile Leu Alaag gag gaa gta aaa ccg gcg ctg gga tgt act gaa ccg att tca 96Val Gln Glu Glu Val Lys Pro Ala Leu Gly Cys Thr Glu Pro Ile Ser 2ctg gcg ctg gcg gcg gcg gtt gct gcg gca gaa ctg gaa ggt ccg gtt Ala Leu Ala Ala Ala Val Ala Ala Ala
Glu Leu Glu Gly Pro Val 35 4 cgt gta gaa gcc tgg gtt tcg cca aat ctg atg aag aac ggt ctg Arg Val Glu Ala Trp Val Ser Pro Asn Leu Met Lys Asn Gly Leu 5ggc gtc acc gtt ccc ggc acg gga atg gtg ggg ctg ccg att gcg gcg 24l Thr Val
Pro Gly Thr Gly Met Val Gly Leu Pro Ile Ala Ala65 7gcg ctg ggg gcg tta ggt gga aat gcc aac gcc ggg ctg gaa gtg ctg 288Ala Leu Gly Ala Leu Gly Gly Asn Ala Asn Ala Gly Leu Glu Val Leu 85 9 gac gca act gcg cag gca att gcc gat gcc aaa gca ctg
ctg gcg 336Lys Asp Ala Thr Ala Gln Ala Ile Ala Asp Ala Lys Ala Leu Leu Ala  ggg aaa gtc tcc gtt aag atc cag gaa cct tgc aat gaa atc ctc 384Ala Gly Lys Val Ser Val Lys Ile Gln Glu Pro Cys Asn Glu Ile Leu  tca cgc gcc aaa gtc
tgg aac ggt gag aag tgg gcg tgt gtc acc 432Phe Ser Arg Ala Lys Val Trp Asn Gly Glu Lys Trp Ala Cys Val Thr  gtc ggc ggg cat acc aac att gtg cat att gag acg cac aat agt 48l Gly Gly His Thr Asn Ile Val His Ile Glu Thr His Asn Ser gtg gtg ttt acc cag cag gcg tgt gtg gca gag ggc gag caa gag tct 528Val Val Phe Thr Gln Gln Ala Cys Val Ala Glu Gly Glu Gln Glu Ser  ctg acg gtg ctt tcc aga acg acg ctg gct gag atc ctg aag ttc 576Pro Leu Thr Val Leu Ser Arg Thr
Thr Leu Ala Glu Ile Leu Lys Phe  aat gaa gtc ccg ttt gcg gcg atc cgc ttt att ctc gat tcc gcg 624Val Asn Glu Val Pro Phe Ala Ala Ile Arg Phe Ile Leu Asp Ser Ala  2ta aat tgt gcg tta tcg cag gaa ggt ttg agc ggt aag tgg ggg
672Lys Leu Asn Cys Ala Leu Ser Gln Glu Gly Leu Ser Gly Lys Trp Gly 222t att ggc gcg acg ctg gaa aaa cag tgc gag cgc ggt ttg ctg 72s Ile Gly Ala Thr Leu Glu Lys Gln Cys Glu Arg Gly Leu Leu225 234a gat ctc tct tca tcc att
gtg att cgt acc agc gcg gca tcc 768Ala Lys Asp Leu Ser Ser Ser Ile Val Ile Arg Thr Ser Ala Ala Ser 245 25t gcg cgt atg ggc ggc gct acg ctt ccg gct atg agt aac tcc ggc 8la Arg Met Gly Gly Ala Thr Leu Pro Ala Met Ser Asn Ser Gly 267t aac cag ggg atc acc gca aca atg cct gtg gtg gtt gta gca 864Ser Gly Asn Gln Gly Ile Thr Ala Thr Met Pro Val Val Val Val Ala 275 28a cac ttc gga gcg gat gat gaa cga ctg gcg cgt gcg ctg atg ctt 9is Phe Gly Ala Asp Asp Glu Arg Leu
Ala Arg Ala Leu Met Leu 29at ttg agc gca att tac atc cat aac cag tta ccg cgt ttg tct 96s Leu Ser Ala Ile Tyr Ile His Asn Gln Leu Pro Arg Leu Ser33ca ctt tgt gcc gca acg acc gca gca atg ggg gcc gcc gcc ggg atg
Leu Cys Ala Ala Thr Thr Ala Ala Met Gly Ala Ala Ala Gly Met 325 33a tgg ctg gtg gat ggg cgt tat gaa act atc tcg atg gcg atc agc  Trp Leu Val Asp Gly Arg Tyr Glu Thr Ile Ser Met Ala Ile Ser 345g atc ggc gat gtc agc ggc atg att
tgc gat ggt gcg tcg aac  Met Ile Gly Asp Val Ser Gly Met Ile Cys Asp Gly Ala Ser Asn 355 36c tgc gcg atg aag gtt tcg acc agt gct tcg gct gcg tgg aaa gcg  Cys Ala Met Lys Val Ser Thr Ser Ala Ser Ala Ala Trp Lys Ala 378a
atg gcg ctg gat gat acc gcc gtg acc ggc aat gaa ggg atc  Leu Met Ala Leu Asp Asp Thr Ala Val Thr Gly Asn Glu Gly Ile385 39cg cat gat gtt gag cag tcg att gcc aac ctg tgt gcg tta gca  Ala His Asp Val Glu Gln Ser Ile Ala Asn Leu
Cys Ala Leu Ala 44at tcg atg cag caa acg gat cgg cag att atc gag att atg gcg  His Ser Met Gln Gln Thr Asp Arg Gln Ile Ile Glu Ile Met Ala 423g gcc aga taa  Lys Ala Arg 4352Shigella boydii 2e Asp Ser
Thr Leu Asn Pro Leu Trp Gln Arg Tyr Ile Leu Alaln Glu Glu Val Lys Pro Ala Leu Gly Cys Thr Glu Pro Ile Ser 2Leu Ala Leu Ala Ala Ala Val Ala Ala Ala Glu Leu Glu Gly Pro Val 35 4 Arg Val Glu Ala Trp Val Ser Pro Asn Leu Met Lys
Asn Gly Leu 5Gly Val Thr Val Pro Gly Thr Gly Met Val Gly Leu Pro Ile Ala Ala65 7Ala Leu Gly Ala Leu Gly Gly Asn Ala Asn Ala Gly Leu Glu Val Leu 85 9 Asp Ala Thr Ala Gln Ala Ile Ala Asp Ala Lys Ala Leu Leu Ala  Gly Lys
Val Ser Val Lys Ile Gln Glu Pro Cys Asn Glu Ile Leu  Ser Arg Ala Lys Val Trp Asn Gly Glu Lys Trp Ala Cys Val Thr  Val Gly Gly His Thr Asn Ile Val His Ile Glu Thr His Asn Ser Val Val Phe Thr Gln Gln Ala Cys Val
Ala Glu Gly Glu Gln Glu Ser  Leu Thr Val Leu Ser Arg Thr Thr Leu Ala Glu Ile Leu Lys Phe  Asn Glu Val Pro Phe Ala Ala Ile Arg Phe Ile Leu Asp Ser Ala  2eu Asn Cys Ala Leu Ser Gln Glu Gly Leu Ser Gly Lys Trp Gly
222s Ile Gly Ala Thr Leu Glu Lys Gln Cys Glu Arg Gly Leu Leu225 234s Asp Leu Ser Ser Ser Ile Val Ile Arg Thr Ser Ala Ala Ser 245 25p Ala Arg Met Gly Gly Ala Thr Leu Pro Ala Met Ser Asn Ser Gly 267y Asn Gln
Gly Ile Thr Ala Thr Met Pro Val Val Val Val Ala 275 28u His Phe Gly Ala Asp Asp Glu Arg Leu Ala Arg Ala Leu Met Leu 29is Leu Ser Ala Ile Tyr Ile His Asn Gln Leu Pro Arg Leu Ser33la Leu Cys Ala Ala Thr Thr Ala Ala Met
Gly Ala Ala Ala Gly Met 325
33a Trp Leu Val Asp Gly Arg Tyr Glu Thr Ile Ser Met Ala Ile Ser 345t Ile Gly Asp Val Ser Gly Met Ile Cys Asp Gly Ala Ser Asn 355 36r Cys Ala Met Lys Val Ser Thr Ser Ala Ser Ala Ala Trp Lys Ala 378u Met
Ala Leu Asp Asp Thr Ala Val Thr Gly Asn Glu Gly Ile385 39la His Asp Val Glu Gln Ser Ile Ala Asn Leu Cys Ala Leu Ala 44is Ser Met Gln Gln Thr Asp Arg Gln Ile Ile Glu Ile Met Ala 423s Ala Arg
43522Citrobacter koseriCDS(tg ttt gag tct aca gaa aat ccg tta tgg cag cgt ttt atc ctc gca 48Met Phe Glu Ser Thr Glu Asn Pro Leu Trp Gln Arg Phe Ile Leu Alaag gaa gag gta aaa ccg gca ctg gga tgt acg gaa cct gtc tct 96Val
Gln Glu Glu Val Lys Pro Ala Leu Gly Cys Thr Glu Pro Val Ser 2ctg gcg ctg gcg gcg gcg gtt gcc gcg gct gaa ctt gac ggc gaa gtt Ala Leu Ala Ala Ala Val Ala Ala Ala Glu Leu Asp Gly Glu Val 35 4 cgc gtt gac gcg tgg gtc tcg ccg aac ctg atg
aag aat ggc ctg Arg Val Asp Ala Trp Val Ser Pro Asn Leu Met Lys Asn Gly Leu 5ggc gtc acc gta ccg ggc acc ggg atg gtt ggg ctt ccc att gcg gca 24l Thr Val Pro Gly Thr Gly Met Val Gly Leu Pro Ile Ala Ala65 7gcg ctg ggg gcg ctt
ggc ggc gat gcc agc gcg ggg ctg gaa gtg ttg 288Ala Leu Gly Ala Leu Gly Gly Asp Ala Ser Ala Gly Leu Glu Val Leu 85 9 aac gcc tct tcg ggg gcg att gcg gat gcg aaa gcg atg ctg gct 336Lys Asn Ala Ser Ser Gly Ala Ile Ala Asp Ala Lys Ala Met Leu Ala  ggg aag gtg tcg gtg atg ttg cag gag cca tgc gac gac atc ctc 384Ala Gly Lys Val Ser Val Met Leu Gln Glu Pro Cys Asp Asp Ile Leu  tca cgc gct aaa gtg tac agc ggc gat gcg tgg gcc tgc gta acg 432Phe Ser Arg Ala Lys Val Tyr Ser Gly
Asp Ala Trp Ala Cys Val Thr  gtc ggc ggg cac acc aat atc gtg cgc att gaa act cac act ggg 48l Gly Gly His Thr Asn Ile Val Arg Ile Glu Thr His Thr Gly gtg atc ttt acg cag acc gaa agc gtg cag ggg gag gcg caa gaa tcg 528Val
Ile Phe Thr Gln Thr Glu Ser Val Gln Gly Glu Ala Gln Glu Ser  ctg tcg gtc tta tca aag acc tcg ctg gaa gag att ctg gcg ttt 576Pro Leu Ser Val Leu Ser Lys Thr Ser Leu Glu Glu Ile Leu Ala Phe  aat gcg gtg cca ttt gtg tca atc cgc
ttt att ctg gag gcc gcc 624Val Asn Ala Val Pro Phe Val Ser Ile Arg Phe Ile Leu Glu Ala Ala  2tg aac ggc gcg ctg tcg cag gaa gga ttg cgc ggc acc tgg ggg 672Arg Leu Asn Gly Ala Leu Ser Gln Glu Gly Leu Arg Gly Thr Trp Gly 222t
atc ggg gcg acg ttg caa aag cag tgc gca cgc ggt ctg ctg 72s Ile Gly Ala Thr Leu Gln Lys Gln Cys Ala Arg Gly Leu Leu225 234c gat ctg tca acg gcg atc ctg att cgc acc agc gca gct tcg 768Ala Asp Asp Leu Ser Thr Ala Ile Leu Ile Arg Thr
Ser Ala Ala Ser 245 25t gcg cgg atg ggc ggc gcg acg ctg cca gcc atg agt aac tcc ggc 8la Arg Met Gly Gly Ala Thr Leu Pro Ala Met Ser Asn Ser Gly 267c aat cag ggg atc acc gcg acg gtt ccc gta atg gtg gtg gcg 864Ser Gly Asn Gln
Gly Ile Thr Ala Thr Val Pro Val Met Val Val Ala 275 28g cat gtg ggg gcg gat gac gaa cgt ctg gcg cgc gcc ctg atg ctc 9is Val Gly Ala Asp Asp Glu Arg Leu Ala Arg Ala Leu Met Leu 29ac ctg agc gcg atc tac att cac cat cag ctt cca
cgc ctg tca 96s Leu Ser Ala Ile Tyr Ile His His Gln Leu Pro Arg Leu Ser33cg ctc tgt gcg gcg acc acg gcg gca atg ggg gcg gcg gca gga atg  Leu Cys Ala Ala Thr Thr Ala Ala Met Gly Ala Ala Ala Gly Met 325 33g tgg ctg atg
gat ggc cgc tat aac acg att gcg atg gcg atc agc  Trp Leu Met Asp Gly Arg Tyr Asn Thr Ile Ala Met Ala Ile Ser 345g atc ggc gac gtg agc ggg atg ata tgc gac ggc gca tcg aat  Met Ile Gly Asp Val Ser Gly Met Ile Cys Asp Gly Ala Ser
Asn 355 36c tgt gcg atg aag gta tcg acc agc gcg tct gcg gcc tgg aaa gcg  Cys Ala Met Lys Val Ser Thr Ser Ala Ser Ala Ala Trp Lys Ala 378a atg gcg ctg gat gat acg gcg gtg acc ggc aac gaa gga att  Leu Met Ala Leu Asp Asp
Thr Ala Val Thr Gly Asn Glu Gly Ile385 39cg cat aac gtc gag caa tct att tcg aat tta tgc gcg ttg gcc  Ala His Asn Val Glu Gln Ser Ile Ser Asn Leu Cys Ala Leu Ala 44at gca atg cag caa acc gac cgt cag gtt atc gaa att atg
gcc  His Ala Met Gln Gln Thr Asp Arg Gln Val Ile Glu Ile Met Ala 423g gcg cat taa  Lys Ala His 43523436PRTCitrobacter koseri 23Met Phe Glu Ser Thr Glu Asn Pro Leu Trp Gln Arg Phe Ile Leu Alaln Glu Glu Val Lys Pro
Ala Leu Gly Cys Thr Glu Pro Val Ser 2Leu Ala Leu Ala Ala Ala Val Ala Ala Ala Glu Leu Asp Gly Glu Val 35 4 Arg Val Asp Ala Trp Val Ser Pro Asn Leu Met Lys Asn Gly Leu 5Gly Val Thr Val Pro Gly Thr Gly Met Val Gly Leu Pro Ile Ala Ala65
7Ala Leu Gly Ala Leu Gly Gly Asp Ala Ser Ala Gly Leu Glu Val Leu 85 9 Asn Ala Ser Ser Gly Ala Ile Ala Asp Ala Lys Ala Met Leu Ala  Gly Lys Val Ser Val Met Leu Gln Glu Pro Cys Asp Asp Ile Leu  Ser Arg Ala Lys Val
Tyr Ser Gly Asp Ala Trp Ala Cys Val Thr  Val Gly Gly His Thr Asn Ile Val Arg Ile Glu Thr His Thr Gly Val Ile Phe Thr Gln Thr Glu Ser Val Gln Gly Glu Ala Gln Glu Ser  Leu Ser Val Leu Ser Lys Thr Ser Leu Glu Glu
Ile Leu Ala Phe  Asn Ala Val Pro Phe Val Ser Ile Arg Phe Ile Leu Glu Ala Ala  2eu Asn Gly Ala Leu Ser Gln Glu Gly Leu Arg Gly Thr Trp Gly 222s Ile Gly Ala Thr Leu Gln Lys Gln Cys Ala Arg Gly Leu Leu225 234p Asp Leu Ser Thr Ala Ile Leu Ile Arg Thr Ser Ala Ala Ser 245 25p Ala Arg Met Gly Gly Ala Thr Leu Pro Ala Met Ser Asn Ser Gly 267y Asn Gln Gly Ile Thr Ala Thr Val Pro Val Met Val Val Ala 275 28u His Val Gly Ala Asp
Asp Glu Arg Leu Ala Arg Ala Leu Met Leu 29is Leu Ser Ala Ile Tyr Ile His His Gln Leu Pro Arg Leu Ser33la Leu Cys Ala Ala Thr Thr Ala Ala Met Gly Ala Ala Ala Gly Met 325 33a Trp Leu Met Asp Gly Arg Tyr Asn Thr Ile Ala
Met Ala Ile Ser 345t Ile Gly Asp Val Ser Gly Met Ile Cys Asp Gly Ala Ser Asn 355 36r Cys Ala Met Lys Val Ser Thr Ser Ala Ser Ala Ala Trp Lys Ala 378u Met Ala Leu Asp Asp Thr Ala Val Thr Gly Asn Glu Gly Ile385 39la His Asn Val Glu Gln Ser Ile Ser Asn Leu Cys Ala Leu Ala 44is Ala Met Gln Gln Thr Asp Arg Gln Val Ile Glu Ile Met Ala 423s Ala His 43524Salmonella typhimuriumCDS(tg ttt gaa tct aaa ata aat cca
ttg tgg caa agt ttt att ctg gcc 48Met Phe Glu Ser Lys Ile Asn Pro Leu Trp Gln Ser Phe Ile Leu Alaag gaa gaa gta aaa ccg gcg ctg ggg tgt act gag cca att tca 96Val Gln Glu Glu Val Lys Pro Ala Leu Gly Cys Thr Glu Pro Ile Ser 2ctg gcg
ctg gcg gca gcg gcg gcg gcg gct gaa ctt aac ggc aca gtt Ala Leu Ala Ala Ala Ala Ala Ala Ala Glu Leu Asn Gly Thr Val 35 4 cgc att gac gcg tgg gtt tcg ccc aat ctg atg aaa aat ggt atg Arg Ile Asp Ala Trp Val Ser Pro Asn Leu Met Lys Asn
Gly Met 5ggc gtt acc gtt cca gga acg gga atg gta ggg cta ccg atc gcc gcg 24l Thr Val Pro Gly Thr Gly Met Val Gly Leu Pro Ile Ala Ala65 7gcg ttg ggc gcg ttg ggc ggt gat gcg aaa gcc ggg ttg gag gtg tta 288Ala Leu Gly Ala Leu Gly Gly
Asp Ala Lys Ala Gly Leu Glu Val Leu 85 9 gac gct tcc gct aaa gcc gtt gcc gat gca aaa gcg atg ctg gcc 336Lys Asp Ala Ser Ala Lys Ala Val Ala Asp Ala Lys Ala Met Leu Ala  gga cat gtc gcg gtg atg ttg cag gag cca tgt aac gat att ctg
384Ala Gly His Val Ala Val Met Leu Gln Glu Pro Cys Asn Asp Ile Leu  tca cgg gcg aaa gtg tat agc ggc gat agc tgg gca tgt gtc acg 432Phe Ser Arg Ala Lys Val Tyr Ser Gly Asp Ser Trp Ala Cys Val Thr  gtc ggc gat cat aca aat att
gtg cgg ata gaa acc gac aag ggt 48l Gly Asp His Thr Asn Ile Val Arg Ile Glu Thr Asp Lys Gly gtg gta ttt acc cag gcc gat aat gcg cag gaa gaa gaa aaa acc tcg 528Val Val Phe Thr Gln Ala Asp Asn Ala Gln Glu Glu Glu Lys Thr Ser
ctg gga gtg ctg tct cat acc tcg ctg gaa gag atc ctg gcg ttt 576Pro Leu Gly Val Leu Ser His Thr Ser Leu Glu Glu Ile Leu Ala Phe  aat gcg gtg ccc ttt gac gct atc cgc ttt att ctc gat gcg gcc 624Val Asn Ala Val Pro Phe Asp Ala Ile Arg
Phe Ile Leu Asp Ala Ala  2ta aac ggc gcg ttg tcg cag gag gga ctg cgt ggt tcc tgg ggg 672Arg Leu Asn Gly Ala Leu Ser Gln Glu Gly Leu Arg Gly Ser Trp Gly 222t atc ggt tcg acg ctg gcc aaa cag tgc gat cgc ggt ctg ctg 72s
Ile Gly Ser Thr Leu Ala Lys Gln Cys Asp Arg Gly Leu Leu225 234a gat ctc tcc acg gcg att ttg atc cgt acc agc gcg gcg tca 768Ala Lys Asp Leu Ser Thr Ala Ile Leu Ile Arg Thr Ser Ala Ala Ser 245 25c gcc aga atg ggc ggt gcc acg ttg ccc
gcg atg agc aac tcc ggc 8la Arg Met Gly Gly Ala Thr Leu Pro Ala Met Ser Asn Ser Gly 267c aac cag ggg att acc gcc acg gtg cca gtc atg gtg gtt gct 864Ser Gly Asn Gln Gly Ile Thr Ala Thr Val Pro Val Met Val Val Ala 275 28a cat
gtc ggc gcc gat gac gag cgc ctg gcg cgc gcg cta atg tta 9is Val Gly Ala Asp Asp Glu Arg Leu Ala Arg Ala Leu Met Leu 29at ttg agc gct atc tat att cac cat cag ctt ccg cgt ttg tcg 96s Leu Ser Ala Ile Tyr Ile His His Gln Leu Pro
Arg Leu Ser33cg ctg tgc gcg gca act acg gcg gcg atg ggc gcg gca gcg ggt atg  Leu Cys Ala Ala Thr Thr Ala Ala Met Gly Ala Ala Ala Gly Met 325 33g tgg ctg ata gat ggt cgt tac gac act atc gca atg gct atc agc  Trp Leu Ile
Asp Gly Arg Tyr Asp Thr Ile Ala Met Ala Ile Ser 345g att ggt gat gtc agc ggg atg att tgc gat ggc gcg tcg aat  Met Ile Gly Asp Val Ser Gly Met Ile Cys Asp Gly Ala Ser Asn 355 36c tgc gcg atg aaa gtc tct acc agc gcg tcg gcg gcg
tgg aaa gcc  Cys Ala Met Lys Val Ser Thr Ser Ala Ser Ala Ala Trp Lys Ala 378g atg gcg ttg gat gat acg gcg gtg acc gga aac gaa ggg att  Leu Met Ala Leu Asp Asp Thr Ala Val Thr Gly Asn Glu Gly Ile385 39cg cac aat
gtc gaa caa tct att tcg aat ttg tgt tcg ctg gcg  Ala His Asn Val Glu Gln Ser Ile Ser Asn Leu Cys Ser Leu Ala 44gc tca atg cag cag acc gac aag cag atc atc gag att atg gcc  Arg Ser Met Gln Gln Thr Asp Lys Gln Ile Ile Glu Ile Met
Ala 423a gcg cat taa  Lys Ala His 43525436PRTSalmonella typhimurium 25Met Phe Glu Ser Lys Ile Asn Pro Leu Trp Gln Ser Phe Ile Leu Alaln Glu Glu Val Lys Pro Ala Leu Gly Cys Thr Glu Pro Ile Ser 2Leu Ala Leu Ala Ala
Ala Ala Ala Ala Ala Glu Leu Asn Gly Thr Val 35 4 Arg Ile Asp Ala Trp Val Ser Pro Asn Leu Met Lys Asn Gly Met 5Gly Val Thr Val Pro Gly Thr Gly Met Val Gly Leu Pro Ile Ala Ala65 7Ala Leu Gly Ala Leu Gly Gly Asp Ala Lys Ala Gly Leu Glu
Val Leu 85 9 Asp Ala Ser Ala Lys Ala Val Ala Asp Ala Lys Ala Met Leu Ala  Gly His Val Ala Val Met Leu Gln Glu Pro Cys Asn Asp Ile Leu  Ser Arg Ala Lys Val Tyr Ser Gly Asp Ser Trp Ala Cys Val Thr  Val Gly
Asp His Thr Asn Ile Val Arg Ile Glu Thr Asp Lys Gly Val Val Phe Thr Gln Ala Asp Asn Ala Gln Glu Glu Glu Lys Thr Ser  Leu Gly Val Leu Ser His Thr Ser Leu Glu Glu Ile Leu Ala Phe  Asn Ala Val Pro Phe Asp Ala Ile
Arg Phe Ile Leu Asp Ala Ala  2eu Asn Gly Ala Leu Ser Gln Glu Gly Leu Arg Gly Ser Trp Gly 222s Ile Gly Ser Thr Leu Ala Lys Gln Cys Asp Arg Gly Leu Leu225 234s Asp Leu Ser Thr Ala Ile Leu Ile Arg Thr Ser Ala Ala
Ser 245 25p Ala Arg Met Gly Gly Ala Thr Leu Pro Ala Met Ser Asn Ser Gly 267y Asn Gln Gly Ile Thr Ala Thr Val Pro Val Met Val Val Ala 275 28u His Val Gly Ala Asp Asp Glu Arg Leu Ala Arg Ala Leu Met Leu 29is Leu
Ser Ala Ile Tyr Ile His His Gln Leu Pro Arg Leu Ser33la Leu Cys Ala Ala Thr Thr Ala Ala Met Gly Ala Ala Ala Gly Met 325 33a Trp Leu Ile Asp Gly Arg Tyr Asp Thr Ile Ala Met Ala Ile Ser 345t Ile Gly Asp Val Ser Gly Met
Ile Cys Asp Gly Ala Ser Asn 355 36r Cys Ala Met Lys Val Ser Thr Ser Ala Ser Ala Ala Trp Lys Ala 378u Met Ala Leu Asp Asp Thr Ala Val Thr Gly Asn Glu Gly Ile385 39la His Asn Val Glu Gln Ser Ile Ser Asn Leu Cys Ser Leu
Ala 44rg Ser Met Gln Gln Thr Asp Lys Gln Ile Ile Glu Ile Met Ala 423s Ala His 43526Actinobacillus pleuropneumoniaeCDS(99) 26atg aag ttt aaa tcg gaa tta gaa caa gcg att att gcc acc gta caa 48Met Lys Phe Lys Ser
Glu Leu Glu Gln Ala Ile Ile Ala Thr Val Glnaa gtt gta ccg gca ctg ggt tgt acc gag cct gtt tct ttg gcg 96Gln Glu Val Val Pro Ala Leu Gly Cys Thr Glu Pro Val Ser Leu Ala 2tta gca gcg gcg gtt gct
cgt caa tat tta ggc gca tta ccg gat cgg Ala Ala Ala Val Ala Arg Gln Tyr Leu Gly Ala Leu Pro Asp Arg 35 4 gag gct aaa gta tcg ccg aat tta atg aaa aac ggt atg ggg gta Glu Ala Lys Val Ser Pro Asn Leu Met Lys Asn Gly Met Gly Val
5acc gta ccc ggt acg gga acg gta gga cta act atg gcg gcg gca atc 24l Pro Gly Thr Gly Thr Val Gly Leu Thr Met Ala Ala Ala Ile65 7gga gcg att ggt ggc gat ccg aac ggc gga ttg gaa gtg ctt aaa cat 288Gly Ala Ile Gly Gly Asp Pro Asn Gly
Gly Leu Glu Val Leu Lys His 85 9 act aac gag caa gtg gca caa gcg aaa caa atg att cac gat cac 336Ile Thr Asn Glu Gln Val Ala Gln Ala Lys Gln Met Ile His Asp His  atc gaa gtc agt att tcc gat acc gaa cat att ctc tat tcc gaa 384Lys Ile
Glu Val Ser Ile Ser Asp Thr Glu His Ile Leu Tyr Ser Glu  aca ctg ttt aat gcc gat cag caa gtg aaa gta cgt atc gcc gct 432Ala Thr Leu Phe Asn Ala Asp Gln Gln Val Lys Val Arg Ile Ala Ala  cat acc aat gtg att tat att gag aaa aac
ggc gaa tta ctg ttt 48s Thr Asn Val Ile Tyr Ile Glu Lys Asn Gly Glu Leu Leu Phe tcc aag cct tgc gta gta gaa agt gaa aat gcg gaa aat gtt ttc gca 528Ser Lys Pro Cys Val Val Glu Ser Glu Asn Ala Glu Asn Val Phe Ala  tta aat
gcg aaa gat att tat gat ttt tct tta aat gtg gag ctg 576Asn Leu Asn Ala Lys Asp Ile Tyr Asp Phe Ser Leu Asn Val Glu Leu  aag att cgc ttt att caa cag gcg gca att tta aat agt gcg ctt 624Glu Lys Ile Arg Phe Ile Gln Gln Ala Ala Ile Leu Asn Ser
Ala Leu  2aa gaa ggg ctg aat caa gat tac ggt tta cat atc ggg cgt acc 672Ser Gln Glu Gly Leu Asn Gln Asp Tyr Gly Leu His Ile Gly Arg Thr 222a aaa caa att ggt aaa gga tta att agc gat gat ttg ctt aat 72n Lys Gln Ile Gly
Lys Gly Leu Ile Ser Asp Asp Leu Leu Asn225 234c gtg att gaa act acc gct gcc agc gat gca cgc atg ggc ggc 768Arg Ile Val Ile Glu Thr Thr Ala Ala Ser Asp Ala Arg Met Gly Gly 245 25a aat tta ccg gcg atg agt aat tcg ggt tcc ggc aac caa
ggg att 8sn Leu Pro Ala Met Ser Asn Ser Gly Ser Gly Asn Gln Gly Ile 267g aca atg ccg gtg gtc gtg gtc gcc cgt cat tta gtt gcg agt 864Thr Ala Thr Met Pro Val Val Val Val Ala Arg His Leu Val Ala Ser 275 28a gaa caa ctg att cga
gcg tta ttt ctt tcg cat tta atg gcg att 9lu Gln Leu Ile Arg Ala Leu Phe Leu Ser His Leu Met Ala Ile 29tt cat agc aaa tta ccg aaa ctc tct gcg tta tgt gcg gtc act 96e His Ser Lys Leu Pro Lys Leu Ser Ala Leu Cys Ala Val Thr33cg gcg gca atg ggc agc tgt gcc ggc gtc gca tgg tta tta acc ggt  Ala Ala Met Gly Ser Cys Ala Gly Val Ala Trp Leu Leu Thr Gly 325 33a ttt gaa gcg atc agt atg gca atc agc agt atg atc ggt gat att  Phe Glu Ala Ile Ser Met Ala
Ile Ser Ser Met Ile Gly Asp Ile 345c att att tgt gac ggt gcg gca aat agc tgc gcg atg aaa gtt  Gly Ile Ile Cys Asp Gly Ala Ala Asn Ser Cys Ala Met Lys Val 355 36a acc agt gtg agt tcc agt tat aaa tcg att tta atg gca ttg gac
Thr Ser Val Ser Ser Ser Tyr Lys Ser Ile Leu Met Ala Leu Asp 378c caa gtg act ggt aac gaa ggg att gtc gaa cac caa atc gac  Thr Gln Val Thr Gly Asn Glu Gly Ile Val Glu His Gln Ile Asp385 39cg atc aac aac ctt tgt
gcg ata gct tcc cgc agt atg caa tat  Ser Ile Asn Asn Leu Cys Ala Ile Ala Ser Arg Ser Met Gln Tyr 44at cgc caa gtg att gag att atg gtg agc aag ccg aaa agc ctg  Asp Arg Gln Val Ile Glu Ile Met Val Ser Lys Pro Lys Ser Leu 4239927432PRTActinobacillus pleuropneumoniae 27Met Lys Phe Lys Ser Glu Leu Glu Gln Ala Ile Ile Ala Thr Val Glnlu Val Val Pro Ala Leu Gly Cys Thr Glu Pro Val Ser Leu Ala 2Leu Ala Ala Ala Val Ala Arg Gln Tyr Leu Gly Ala Leu Pro
Asp Arg 35 4 Glu Ala Lys Val Ser Pro Asn Leu Met Lys Asn Gly Met Gly Val 5Thr Val Pro Gly Thr Gly Thr Val Gly Leu Thr Met Ala Ala Ala Ile65 7Gly Ala Ile Gly Gly Asp Pro Asn Gly Gly Leu Glu Val Leu Lys His 85 9 Thr Asn Glu Gln
Val Ala Gln Ala Lys Gln Met Ile His Asp His  Ile Glu Val Ser Ile Ser Asp Thr Glu His Ile Leu Tyr Ser Glu  Thr Leu Phe Asn Ala Asp Gln Gln Val Lys Val Arg Ile Ala Ala  His Thr Asn Val Ile Tyr Ile Glu Lys Asn Gly
Glu Leu Leu Phe Ser Lys Pro Cys Val Val Glu Ser Glu Asn Ala Glu Asn Val Phe Ala  Leu Asn Ala Lys Asp Ile Tyr Asp Phe Ser Leu Asn Val Glu Leu  Lys Ile Arg Phe Ile Gln Gln Ala Ala Ile Leu Asn Ser Ala Leu
2ln Glu Gly Leu Asn Gln Asp Tyr Gly Leu His Ile Gly Arg Thr 222n Lys Gln Ile Gly Lys Gly Leu Ile Ser Asp Asp Leu Leu Asn225 234e Val Ile Glu Thr Thr Ala Ala Ser Asp Ala Arg Met Gly Gly 245 25a Asn Leu Pro Ala Met
Ser Asn Ser Gly Ser Gly Asn Gln Gly Ile 267a Thr Met Pro Val Val Val Val Ala Arg His Leu Val Ala Ser 275 28u Glu Gln Leu Ile Arg Ala Leu Phe Leu Ser His Leu Met Ala Ile 29le His Ser Lys Leu Pro Lys Leu Ser Ala Leu Cys
Ala Val Thr33hr Ala Ala Met Gly Ser Cys Ala Gly Val Ala Trp Leu Leu Thr Gly 325 33s Phe Glu Ala Ile Ser Met Ala Ile Ser Ser Met Ile Gly Asp Ile 345y Ile Ile Cys Asp Gly Ala Ala Asn Ser Cys Ala Met Lys Val 355 36r
Thr Ser Val Ser Ser Ser Tyr Lys Ser Ile Leu Met Ala Leu Asp 378r Gln Val Thr Gly Asn Glu Gly Ile Val Glu His Gln Ile Asp385 39er Ile Asn Asn Leu Cys Ala Ile Ala Ser Arg Ser Met Gln Tyr 44sp Arg Gln Val Ile Glu
Ile Met Val Ser Lys Pro Lys Ser Leu 423DNAKlebsiella pneumoniaeCDS(78) 28atg aac acc gat aac gct tcc ctg tac gta aaa tgg ctc aaa caa gag 48Met Asn Thr Asp Asn Ala Ser Leu Tyr Val Lys Trp Leu Lys Gln Glucc ccg gct tta
ggt tgt act gaa ccc gtc gct att tcc ttc gcg 96Val Ala Pro Ala Leu Gly Cys Thr Glu Pro Val Ala Ile Ser Phe Ala 2gcc gcc tac gcc gca caa tat ctg gat cag cct tgc act aaa att agc Ala Tyr Ala Ala Gln Tyr Leu Asp Gln Pro Cys Thr Lys Ile Ser 35 4 ttt att tcc gcc aat ctt tat aaa aac gcg atg ggc gtc acc ata Phe Ile Ser Ala Asn Leu Tyr Lys Asn Ala Met Gly Val Thr Ile 5ccc ggc acc acc gtt tgc ggt gta ccg ctg gca gcc gca att ggc gca 24y Thr Thr Val Cys Gly Val Pro Leu Ala
Ala Ala Ile Gly Ala65 7ttt ggc ggc gac ccg caa aag gga tta aaa acg ctg gaa gat atc act 288Phe Gly Gly Asp Pro Gln Lys Gly Leu Lys Thr Leu Glu Asp Ile Thr 85 9 caa cac gtt gaa atg gcg cag aag ctg atc gcc aat aac gcc gtt 336Pro Gln His Val
Glu Met Ala Gln Lys Leu Ile Ala Asn Asn Ala Val  att gcc gtc gaa gag act cct gat ttt att cat ctc gat cta acc 384Asp Ile Ala Val Glu Glu Thr Pro Asp Phe Ile His Leu Asp Leu Thr  tct gct ggc gat aat tgc tgt cgt gtc gtg gtc aaa
gga acc cac 432Leu Ser Ala Gly Asp Asn Cys Cys Arg Val Val Val Lys Gly Thr His  aac gtg gtc gaa ctt tat att aat ggc cag ccg cag cca tta agc 48n Val Val Glu Leu Tyr Ile Asn Gly Gln Pro Gln Pro Leu Ser gaa aaa cag aat acg
cgc acc cag cgc gaa acg ctg ccc act ttc tcg 528Glu Lys Gln Asn Thr Arg Thr Gln Arg Glu Thr Leu Pro Thr Phe Ser  caa cag gct tac gac ttt att aat cgc gtc gac ttt aat gat att 576Leu Gln Gln Ala Tyr Asp Phe Ile Asn Arg Val Asp Phe Asn Asp Ile
ttt att ctc gac gcc gcg cgc tta aac tcc gcg ctg gcg gca gaa 624Arg Phe Ile Leu Asp Ala Ala Arg Leu Asn Ser Ala Leu Ala Ala Glu  2aa aca aaa aaa tat ggc ctg aac att aac ggt acc ttt tct gac 672Gly Lys Thr Lys Lys Tyr Gly Leu
Asn Ile Asn Gly Thr Phe Ser Asp 222g aaa aac ggc ctg atg agc aac gat ctg tta agc aag gtg atc 72l Lys Asn Gly Leu Met Ser Asn Asp Leu Leu Ser Lys Val Ile225 234c acc gtc gcc gct tca gat gcc cgc atg ggc ggc gcg ccg gtg
768Ile Asn Thr Val Ala Ala Ser Asp Ala Arg Met Gly Gly Ala Pro Val 245 25a gcg atg tct aac ttc ggc tca ggc aat cag ggc att aca gca acc 8la Met Ser Asn Phe Gly Ser Gly Asn Gln Gly Ile Thr Ala Thr 267g gta gtg gtg gtt gca gag
cat ctc ggc gtc gat gaa gag acc 864Met Pro Val Val Val Val Ala Glu His Leu Gly Val Asp Glu Glu Thr 275 28g gct cgc gct ttg tct ctc tct cat ctc acc gcc atc tca att cat 9la Arg Ala Leu Ser Leu Ser His Leu Thr Ala Ile Ser Ile His 29gt tac acg cgc tta tct gcg cta tgc gca gcc tca acc gcc gct 96g Tyr Thr Arg Leu Ser Ala Leu Cys Ala Ala Ser Thr Ala Ala33tg ggc gcc gcc gcc ggt atg gcc tgg ctg ttt acc cgc gac atc aac  Gly Ala Ala Ala Gly Met Ala Trp
Leu Phe Thr Arg Asp Ile Asn 325 33g att aat acc gcg att att aat atg atc agc gat att acc ggc atg  Ile Asn Thr Ala Ile Ile Asn Met Ile Ser Asp Ile Thr Gly Met 345t gat ggc gct tcc aac agc tgc gcg atg aaa gtc tcg tca gtg
Cys Asp Gly Ala Ser Asn Ser Cys Ala Met Lys Val Ser Ser Val 355 36a tcc agc gcc ttt aag gcg gta cta atg gcc atg caa aat agc tgt  Ser Ser Ala Phe Lys Ala Val Leu Met Ala Met Gln Asn Ser Cys 378c gcc aat gac ggt att gtc tgc gct
gat gtt gag caa acc att  Gly Ala Asn Asp Gly Ile Val Cys Ala Asp Val Glu Gln Thr Ile385 39ac tta tgc cgt ctg gtg att aaa cca atg act ctc acc gat aaa  Asn Leu Cys Arg Leu Val Ile Lys Pro Met Thr Leu Thr Asp Lys 44tt atc agc att atg gtc gct aaa taa  Ile Ile Ser Ile Met Val Ala Lys 42425PRTKlebsiella pneumoniae 29Met Asn Thr Asp Asn Ala Ser Leu Tyr Val Lys Trp Leu Lys Gln Glula Pro Ala Leu Gly Cys Thr Glu Pro Val Ala Ile Ser Phe Ala 2Ala Ala Tyr Ala Ala Gln Tyr Leu Asp Gln Pro Cys Thr Lys Ile Ser 35 4 Phe Ile Ser Ala Asn Leu Tyr Lys Asn Ala Met Gly Val Thr Ile 5Pro Gly Thr Thr Val Cys Gly Val Pro Leu Ala Ala Ala Ile Gly Ala65 7Phe Gly Gly Asp Pro Gln Lys Gly
Leu Lys Thr Leu Glu Asp Ile Thr 85 9 Gln His Val Glu Met Ala Gln Lys Leu Ile Ala Asn Asn Ala Val  Ile Ala Val Glu Glu Thr Pro Asp Phe Ile His Leu Asp Leu Thr  Ser Ala Gly Asp Asn Cys Cys Arg Val Val Val Lys Gly Thr His
Asn Val Val Glu Leu Tyr Ile Asn Gly Gln Pro Gln Pro Leu Ser Glu Lys Gln Asn Thr Arg Thr Gln Arg Glu Thr Leu Pro Thr Phe Ser  Gln Gln Ala Tyr Asp Phe Ile Asn Arg Val Asp Phe Asn Asp Ile  Phe Ile Leu
Asp Ala Ala Arg Leu Asn Ser Ala Leu Ala Ala Glu  2ys Thr Lys Lys Tyr Gly Leu Asn Ile Asn Gly Thr Phe Ser Asp 222l Lys Asn Gly Leu Met Ser Asn Asp Leu Leu Ser Lys Val Ile225 234n Thr Val Ala Ala Ser Asp Ala Arg
Met Gly Gly Ala Pro Val 245 25l Ala Met Ser Asn Phe Gly Ser Gly Asn Gln Gly Ile Thr Ala Thr 267o Val Val Val Val Ala Glu His Leu Gly Val Asp Glu Glu Thr 275 28u Ala Arg Ala Leu Ser Leu Ser His Leu Thr Ala Ile Ser Ile His 29rg Tyr Thr Arg Leu Ser Ala Leu Cys Ala Ala Ser Thr Ala Ala33et Gly Ala Ala Ala Gly Met Ala Trp Leu Phe Thr Arg Asp Ile Asn 325 33r Ile Asn Thr Ala Ile Ile Asn Met Ile Ser Asp Ile Thr Gly Met 345s Asp Gly Ala
Ser Asn Ser Cys Ala Met Lys Val Ser Ser Val 355 36l Ser Ser Ala Phe Lys Ala Val Leu Met Ala Met Gln Asn Ser Cys 378y Ala Asn Asp Gly Ile Val Cys Ala Asp Val Glu Gln Thr Ile385 39sn Leu Cys Arg Leu Val Ile Lys Pro Met
Thr Leu Thr Asp Lys 44le Ile Ser Ile Met Val Ala Lys 42Vibrio fischeriCDS(78) 3c tct atc tgg aaa cag tac att gat att tta caa ggt gtt gta 48Met Asn Ser Ile Trp Lys Gln Tyr Ile Asp Ile Leu Gln Gly Val Valca gct ctt ggt tgt act gaa cca att tgt gcc gct tat gct gca 96Lys Pro Ala Leu Gly Cys Thr Glu Pro Ile Cys Ala Ala Tyr Ala Ala 2agc gtg gct aca caa atg ctt ggt tct aaa cca gaa aca ata gac gtt Val Ala Thr Gln Met Leu Gly Ser Lys Pro Glu
Thr Ile Asp Val 35 4 gtt tct gat aac tta tac aaa aat agc atg ggt gtt ttt gta cca Val Ser Asp Asn Leu Tyr Lys Asn Ser Met Gly Val Phe Val Pro 5aga aca ggt aga gtt ggc ctt gct att gca gcg gca act ggg gca ata 24r Gly Arg Val Gly
Leu Ala Ile Ala Ala Ala Thr Gly Ala Ile65 7ggt ggt aat cct gat gca ggc tta gaa gta tta gca aag ata act gaa 288Gly Gly Asn Pro Asp Ala Gly Leu Glu Val Leu Ala Lys Ile Thr Glu 85 9 gaa gta gat gaa gca caa aag ctc att gat aat ggc tgt gta gtc
336Glu Glu Val Asp Glu Ala Gln Lys Leu Ile Asp Asn Gly Cys Val Val  caa aga gaa acc act gac gag ttt att tat tgt cga gtt att gct 384Val Gln Arg Glu Thr Thr Asp Glu Phe Ile Tyr Cys Arg Val Ile Ala  aat gcg gtt cat aat gct gaa
gtt acg att agc ggt ggt cac act 432Lys Asn Ala Val His Asn Ala Glu Val Thr Ile Ser Gly Gly His Thr  att att gaa aaa cgt ctt gat gat aac gtc att ttc acg ctg gat 48e Ile Glu Lys Arg Leu Asp Asp Asn Val Ile Phe Thr Leu Asp tcc tct tta cca aaa aca tct aca gcg tca
att tgt gat ggc gtt gat 528Ser Ser Leu Pro Lys Thr Ser Thr Ala Ser Ile Cys Asp Gly Val Asp  act atc tca tca att tat gac ttt gct acc caa gca gag ttt gac 576Ile Thr Ile Ser Ser Ile Tyr Asp Phe Ala Thr Gln Ala Glu Phe Asp
att aaa ttt att tta gag gca aaa gag tta aat atc gct ctc gct 624Asp Ile Lys Phe Ile Leu Glu Ala Lys Glu Leu Asn Ile Ala Leu Ala  2aa ggt tta aat aac cct tac ggt tta gaa gtc ggc cga acc tat 672Gln Glu Gly Leu Asn Asn Pro Tyr Gly Leu
Glu Val Gly Arg Thr Tyr 222g aac att gaa aaa gga tta ctt gct aaa agt cta gat agt gac 72s Asn Ile Glu Lys Gly Leu Leu Ala Lys Ser Leu Asp Ser Asp225 234g atc tat act tct gca gca tct gac gct cgt atg gga ggg gcg 768Ile Leu
Ile Tyr Thr Ser Ala Ala Ser Asp Ala Arg Met Gly Gly Ala 245 25a cta cca gcc atg tcg aat tat ggc agt ggt aac caa ggt att gca 8eu Pro Ala Met Ser Asn Tyr Gly Ser Gly Asn Gln Gly Ile Ala 267t att cca gta gta aaa atg gct gac ttt
ttt aat gct gat gat 864Ala Thr Ile Pro Val Val Lys Met Ala Asp Phe Phe Asn Ala Asp Asp 275 28a aaa tta gct cga gct ttt atc atg agt cat ctt ggt gcc att tat 9ys Leu Ala Arg Ala Phe Ile Met Ser His Leu Gly Ala Ile Tyr 29aa tct
cac tac cca cca ctt tct gct ttt tgt ggt aat gct gtt 96s Ser His Tyr Pro Pro Leu Ser Ala Phe Cys Gly Asn Ala Val33ct tct gca gca gca tca atg gcg atg gta tat cta gct ggt ggc acg  Ser Ala Ala Ala Ser Met Ala Met Val Tyr Leu Ala
Gly Gly Thr 325 33t gaa caa tct tgc tca gcc att caa aat acc atc agt gat acc agc  Glu Gln Ser Cys Ser Ala Ile Gln Asn Thr Ile Ser Asp Thr Ser 345g att tgt gac ggt gca aaa tca acg tgt gcg atg aaa gtg gga  Met Ile Cys Asp
Gly Ala Lys Ser Thr Cys Ala Met Lys Val Gly 355 36t agc gct caa tca gca atg aaa tct gct cta tta gca cta aat gat  Ser Ala Gln Ser Ala Met Lys Ser Ala Leu Leu Ala Leu Asn Asp 378t gta acg aag caa ggt gtg att gct gat gat gtt gaa
aag aca  Cys Val Thr Lys Gln Gly Val Ile Ala Asp Asp Val Glu Lys Thr385 39aa aac att ggc aga atg atc aca aca ggt atg cct aat att gat  Lys Asn Ile Gly Arg Met Ile Thr Thr Gly Met Pro Asn Ile Asp 44aa atc att gaa
ata atg gcg tca taa  Glu Ile Ile Glu Ile Met Ala Ser 42425PRTVibrio fischeri 3n Ser Ile Trp Lys Gln Tyr Ile Asp Ile Leu Gln Gly Val Valro Ala Leu Gly Cys Thr Glu Pro Ile Cys Ala Ala Tyr Ala Ala 2Ser Val Ala Thr
Gln Met Leu Gly Ser Lys Pro Glu Thr Ile Asp Val 35 4 Val Ser Asp Asn Leu Tyr Lys Asn Ser Met Gly Val Phe Val Pro 5Arg Thr Gly Arg Val Gly Leu Ala Ile Ala Ala Ala Thr Gly Ala Ile65 7Gly Gly Asn Pro Asp Ala Gly Leu Glu Val Leu Ala Lys
Ile Thr Glu 85 9 Glu Val Asp Glu Ala Gln Lys Leu Ile Asp Asn Gly Cys Val Val  Gln Arg Glu Thr Thr Asp Glu Phe Ile Tyr Cys Arg Val Ile Ala  Asn Ala Val His Asn Ala Glu Val Thr Ile Ser Gly Gly His Thr  Ile
Ile Glu Lys Arg Leu Asp Asp Asn Val Ile Phe Thr Leu Asp Ser Ser Leu Pro Lys Thr Ser Thr Ala Ser Ile Cys Asp Gly Val Asp  Thr Ile Ser Ser Ile Tyr Asp Phe Ala Thr Gln Ala Glu Phe Asp  Ile Lys Phe Ile Leu Glu Ala
Lys Glu Leu Asn Ile Ala Leu Ala  2lu Gly Leu Asn Asn Pro Tyr Gly Leu Glu Val Gly Arg Thr Tyr 222s Asn Ile Glu Lys Gly Leu Leu Ala Lys Ser Leu Asp Ser Asp225 234u Ile Tyr Thr Ser Ala Ala Ser Asp Ala Arg Met Gly
Gly Ala 245 25r Leu Pro Ala Met Ser Asn Tyr Gly Ser Gly Asn Gln Gly Ile Ala 267r Ile Pro Val Val Lys Met Ala Asp Phe Phe Asn Ala Asp Asp 275 28u Lys Leu Ala Arg Ala Phe Ile Met Ser His Leu Gly Ala Ile Tyr 29ys
Ser His Tyr Pro Pro Leu Ser Ala Phe Cys Gly Asn Ala Val33hr Ser Ala Ala Ala Ser Met Ala Met Val Tyr Leu Ala Gly Gly Thr 325 33e Glu Gln Ser Cys Ser Ala Ile Gln Asn Thr Ile Ser Asp Thr Ser 345t Ile Cys Asp Gly Ala Lys
Ser Thr Cys Ala Met Lys Val Gly 355 36r Ser Ala Gln Ser Ala Met Lys Ser Ala Leu Leu Ala Leu Asn Asp 378s Val Thr Lys Gln Gly Val Ile Ala Asp Asp Val Glu Lys Thr385 39ys Asn Ile Gly Arg Met Ile Thr Thr Gly Met Pro Asn
Ile Asp 44lu Ile Ile Glu Ile Met Ala Ser 42BR&gt;
L-cysteine-producing bacterium and a method for producing L-cysteine, Nonaka, et al., Gen Nonaka, Kazuhiro Takumi, Application number 12 397-666, Chemistry: Molecular Biology And Microbiology, Chemistry: Natural Resins Or Derivatives, Peptides Or Proteins, Lignins Or Reaction Products Thereof, Organic Compounds -- Part Of The Class 532-570 Series
This application claims priority under 35 U.S.C. .sctn.119 to Japanese Patent Application No.2008-056362, filed on Mar. 6, 2008, which is incorporated in its entirety by reference. The Sequence Listing in electronic format filed herewith is also hereby incorporated by reference in its entirety (File Name: US-385_Seq_List; File Size: 72 KB;Date Created: Mar. 4, 2009).BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing L-cysteine or related substances. Specifically, the present invention relates to a bacterium suitable for the production of L-cysteine or related substances and a method for producingL-cysteine or related substances utilizing such a bacterium. L-cysteine and L-cysteine-related substances are used in the fields of drugs, cosmetics, and foods. 2. Brief Description of the Related Art L-cysteine is conventionally obtained by extraction from keratin-containing substances such as hairs, horns, and feathers, or by conversion of DL-2-aminothiazoline-4-carboxylic acid using a microbial enzyme. L-cysteine has also been produced ona large scale by using an immobilized enzyme method and a novel enzyme. Furthermore, it has also been attempted to produce L-cysteine by fermentation utilizing a microorganism. Microorganisms which are able to produce L-cysteine are known. For example, a coryneform bacterium with increased intracellular serine acetyltransferase activity produces cysteine (Japanese Patent Laid-open (Kokai) No. 2002-233384). L-cysteine-producing ability can also be increased by incorporating serine acetyltransferase which has been mutated to attenuate feedback inhibition by L-cysteine (Japanese Patent Laid-open No. 11-155571, U.S. Patent Published Application No.20050112731, U.S. Pat. No. 6,218,168). Furthermore, L-cysteine-producing ability in a microorganism can be enhanced by suppressing the L-cysteine decomposition system. Examples of such microorganisms include coryneform bacter
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