ID   CYSK_BUCAP              Reviewed;         322 AA.
AC   Q8KA48;
DT   08-NOV-2002, integrated into UniProtKB/Swiss-Prot.
DT   01-OCT-2002, sequence version 1.
DT   03-AUG-2022, entry version 113.
DE   RecName: Full=Cysteine synthase;
DE            Short=CSase;
DE            EC=2.5.1.47;
DE   AltName: Full=O-acetylserine (thiol)-lyase;
DE            Short=OAS-TL;
DE   AltName: Full=O-acetylserine sulfhydrylase;
GN   Name=cysK; OrderedLocusNames=BUsg_063;
OS   Buchnera aphidicola subsp. Schizaphis graminum (strain Sg).
OC   Bacteria; Proteobacteria; Gammaproteobacteria; Enterobacterales;
OC   Erwiniaceae; Buchnera.
OX   NCBI_TaxID=198804;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=Sg;
RX   PubMed=12089438; DOI=10.1126/science.1071278;
RA   Tamas I., Klasson L., Canbaeck B., Naeslund A.K., Eriksson A.-S.,
RA   Wernegreen J.J., Sandstroem J.P., Moran N.A., Andersson S.G.E.;
RT   "50 million years of genomic stasis in endosymbiotic bacteria.";
RL   Science 296:2376-2379(2002).
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=hydrogen sulfide + O-acetyl-L-serine = acetate + L-cysteine;
CC         Xref=Rhea:RHEA:14829, ChEBI:CHEBI:29919, ChEBI:CHEBI:30089,
CC         ChEBI:CHEBI:35235, ChEBI:CHEBI:58340; EC=2.5.1.47;
CC   -!- COFACTOR:
CC       Name=pyridoxal 5'-phosphate; Xref=ChEBI:CHEBI:597326;
CC         Evidence={ECO:0000250};
CC   -!- PATHWAY: Amino-acid biosynthesis; L-cysteine biosynthesis; L-cysteine
CC       from L-serine: step 2/2.
CC   -!- SUBUNIT: Homodimer. {ECO:0000250}.
CC   -!- SIMILARITY: Belongs to the cysteine synthase/cystathionine beta-
CC       synthase family. {ECO:0000305}.
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DR   EMBL; AE013218; AAM67634.1; -; Genomic_DNA.
DR   RefSeq; WP_011053600.1; NC_004061.1.
DR   AlphaFoldDB; Q8KA48; -.
DR   SMR; Q8KA48; -.
DR   STRING; 198804.BUsg_063; -.
DR   EnsemblBacteria; AAM67634; AAM67634; BUsg_063.
DR   KEGG; bas:BUsg_063; -.
DR   eggNOG; COG0031; Bacteria.
DR   HOGENOM; CLU_021018_1_2_6; -.
DR   OMA; FWDSGER; -.
DR   OrthoDB; 1033353at2; -.
DR   UniPathway; UPA00136; UER00200.
DR   Proteomes; UP000000416; Chromosome.
DR   GO; GO:0004124; F:cysteine synthase activity; IEA:UniProtKB-EC.
DR   GO; GO:0006535; P:cysteine biosynthetic process from serine; IEA:InterPro.
DR   Gene3D; 3.40.50.1100; -; 2.
DR   InterPro; IPR005856; Cys_synth.
DR   InterPro; IPR005859; CysK.
DR   InterPro; IPR001216; P-phosphate_BS.
DR   InterPro; IPR001926; PLP-dep.
DR   InterPro; IPR036052; Trypto_synt_PLP_dependent.
DR   Pfam; PF00291; PALP; 1.
DR   SUPFAM; SSF53686; SSF53686; 1.
DR   TIGRFAMs; TIGR01139; cysK; 1.
DR   TIGRFAMs; TIGR01136; cysKM; 1.
DR   PROSITE; PS00901; CYS_SYNTHASE; 1.
PE   3: Inferred from homology;
KW   Allosteric enzyme; Amino-acid biosynthesis; Cysteine biosynthesis;
KW   Pyridoxal phosphate; Transferase.
FT   CHAIN           1..322
FT                   /note="Cysteine synthase"
FT                   /id="PRO_0000167084"
FT   BINDING         8
FT                   /ligand="hydrogen sulfide"
FT                   /ligand_id="ChEBI:CHEBI:29919"
FT                   /ligand_note="allosteric inhibitor; ligand shared between
FT                   dimeric partners"
FT                   /evidence="ECO:0000250|UniProtKB:P0A1E3"
FT   BINDING         35
FT                   /ligand="hydrogen sulfide"
FT                   /ligand_id="ChEBI:CHEBI:29919"
FT                   /ligand_note="allosteric inhibitor; ligand shared between
FT                   dimeric partners"
FT                   /note="in other chain"
FT                   /evidence="ECO:0000250|UniProtKB:P0A1E3"
FT   BINDING         72
FT                   /ligand="pyridoxal 5'-phosphate"
FT                   /ligand_id="ChEBI:CHEBI:597326"
FT                   /evidence="ECO:0000250"
FT   BINDING         177..181
FT                   /ligand="pyridoxal 5'-phosphate"
FT                   /ligand_id="ChEBI:CHEBI:597326"
FT                   /evidence="ECO:0000250"
FT   BINDING         269
FT                   /ligand="hydrogen sulfide"
FT                   /ligand_id="ChEBI:CHEBI:29919"
FT                   /ligand_note="allosteric inhibitor; ligand shared between
FT                   dimeric partners"
FT                   /note="in other chain"
FT                   /evidence="ECO:0000250|UniProtKB:P0A1E3"
FT   BINDING         273
FT                   /ligand="pyridoxal 5'-phosphate"
FT                   /ligand_id="ChEBI:CHEBI:597326"
FT                   /evidence="ECO:0000250"
FT   MOD_RES         42
FT                   /note="N6-(pyridoxal phosphate)lysine"
FT                   /evidence="ECO:0000250"
SQ   SEQUENCE   322 AA;  35177 MW;  52BA593760519D52 CRC64;
     MNKIYEDNSF TIGNTPLVRL NNIGNGNILA KIESRNPSFS VKCRIGANMI WDAEKKGRLN
     KNIEIIEATS GNTGIALAYV AAARNYSLTL IMPDSMSIER RKLLKSLGAH LILTNGKHGM
     KGAISKANEI VSLNTKRYLL LKQFENPANP EIHQKTTGPE IWKDTKGNID ILISGVGTGG
     TITGITKYIK IKEGKKDLIS VAVEPLESPV ITQFLSGKKI KPGLHKIQGI GAGFIPKNLD
     LSLIDRIITV SSEEAIFNAK KIMKKEGILS GISSGAAIAA ALKIQKENDF KNKNIVVILP
     SSGERYLSTE LFSRSFKNEN NY