ID   CAS1_SOLTU              Reviewed;         351 AA.
AC   Q76MX2;
DT   05-SEP-2012, integrated into UniProtKB/Swiss-Prot.
DT   19-JUL-2004, sequence version 1.
DT   03-AUG-2022, entry version 87.
DE   RecName: Full=Bifunctional L-3-cyanoalanine synthase/cysteine synthase 1, mitochondrial;
DE            EC=2.5.1.47 {ECO:0000269|PubMed:10795315, ECO:0000269|PubMed:11575729};
DE            EC=4.4.1.9 {ECO:0000269|PubMed:10795315, ECO:0000269|PubMed:11575729};
DE   Flags: Precursor;
GN   Name=PCAS-1;
OS   Solanum tuberosum (Potato).
OC   Eukaryota; Viridiplantae; Streptophyta; Embryophyta; Tracheophyta;
OC   Spermatophyta; Magnoliopsida; eudicotyledons; Gunneridae; Pentapetalae;
OC   asterids; lamiids; Solanales; Solanaceae; Solanoideae; Solaneae; Solanum.
OX   NCBI_TaxID=4113;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [MRNA], CATALYTIC ACTIVITY, BIOPHYSICOCHEMICAL
RP   PROPERTIES, TISSUE SPECIFICITY, INDUCTION BY ETHYLENE METHYL JASMONATE AND
RP   WOUNDING, AND FUNCTION.
RC   STRAIN=cv. Dansyaku;
RX   PubMed=11575729; DOI=10.1023/a:1011629703784;
RA   Maruyama A., Saito K., Ishizawa K.;
RT   "Beta-cyanoalanine synthase and cysteine synthase from potato: molecular
RT   cloning, biochemical characterization, and spatial and hormonal
RT   regulation.";
RL   Plant Mol. Biol. 46:749-760(2001).
RN   [2]
RP   PROTEIN SEQUENCE OF 76-84 AND 316-332, CATALYTIC ACTIVITY,
RP   BIOPHYSICOCHEMICAL PROPERTIES, AND SUBUNIT.
RC   STRAIN=cv. Dansyaku;
RX   PubMed=10795315; DOI=10.1093/pcp/41.2.200;
RA   Maruyama A., Ishizawa K., Takagi T.;
RT   "Purification and characterization of beta-cyanoalanine synthase and
RT   cysteine synthases from potato tubers: are beta-cyanoalanine synthase and
RT   mitochondrial cysteine synthase same enzyme?";
RL   Plant Cell Physiol. 41:200-208(2000).
CC   -!- FUNCTION: The cyanoalanine synthesis reaction is more efficient than
CC       the cysteine synthase activity. Probably involved in detoxification of
CC       toxic cyanide produced in plant tissues. {ECO:0000269|PubMed:11575729}.
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         Evidence={ECO:0000269|PubMed:10795315, ECO:0000269|PubMed:11575729};
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=hydrogen cyanide + L-cysteine = 3-cyano-L-alanine + H(+) +
CC         hydrogen sulfide; Xref=Rhea:RHEA:17821, ChEBI:CHEBI:15378,
CC         ChEBI:CHEBI:18407, ChEBI:CHEBI:29919, ChEBI:CHEBI:35235,
CC         ChEBI:CHEBI:77860; EC=4.4.1.9; Evidence={ECO:0000269|PubMed:10795315,
CC         ECO:0000269|PubMed:11575729};
CC   -!- COFACTOR:
CC       Name=pyridoxal 5'-phosphate; Xref=ChEBI:CHEBI:597326;
CC         Evidence={ECO:0000305};
CC   -!- BIOPHYSICOCHEMICAL PROPERTIES:
CC       Kinetic parameters:
CC         KM=2.76 mM for L-cysteine for the L-3-cyanoalanine synthase activity
CC         (in the presence of 5 mM KCN) {ECO:0000269|PubMed:10795315,
CC         ECO:0000269|PubMed:11575729};
CC         KM=0.134 mM for CN for the L-3-cyanoalanine synthase activity (in the
CC         presence of 5 mM L-cysteine) {ECO:0000269|PubMed:10795315,
CC         ECO:0000269|PubMed:11575729};
CC         KM=2.77 mM for O(3)-acetyl-L-serine for the cysteine synthase
CC         activity (in the presence of 2.5 mM Na(2)S)
CC         {ECO:0000269|PubMed:10795315, ECO:0000269|PubMed:11575729};
CC         KM=0.746 mM for Na(2)S for the cysteine synthase activity (in the
CC         presence of 10 mM O(3)-acetyl-L-serine) {ECO:0000269|PubMed:10795315,
CC         ECO:0000269|PubMed:11575729};
CC       pH dependence:
CC         Optimum pH is 8.0-9.0. {ECO:0000269|PubMed:10795315,
CC         ECO:0000269|PubMed:11575729};
CC   -!- SUBUNIT: Homodimer. {ECO:0000269|PubMed:10795315}.
CC   -!- SUBCELLULAR LOCATION: Mitochondrion {ECO:0000305}.
CC   -!- TISSUE SPECIFICITY: Expressed in tubers and buds. Detected in leaves.
CC       {ECO:0000269|PubMed:11575729}.
CC   -!- INDUCTION: Up-regulated at the protein level by ethylene and 1-
CC       Aminocyclopropane-1-carboxylic acid or naphthalene acetic acid
CC       treatments. Down-regulated at transcript level by methyl jasmonate. No
CC       effect from wounding. {ECO:0000269|PubMed:11575729}.
CC   -!- SIMILARITY: Belongs to the cysteine synthase/cystathionine beta-
CC       synthase family. {ECO:0000305}.
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DR   EMBL; AB027000; BAB18760.1; -; mRNA.
DR   RefSeq; NP_001305620.1; NM_001318691.1.
DR   AlphaFoldDB; Q76MX2; -.
DR   SMR; Q76MX2; -.
DR   IntAct; Q76MX2; 1.
DR   STRING; 4113.PGSC0003DMT400016646; -.
DR   GeneID; 102604154; -.
DR   KEGG; sot:102604154; -.
DR   eggNOG; KOG1252; Eukaryota.
DR   InParanoid; Q76MX2; -.
DR   BRENDA; 4.4.1.9; 5757.
DR   SABIO-RK; Q76MX2; -.
DR   Proteomes; UP000011115; Unassembled WGS sequence.
DR   ExpressionAtlas; Q76MX2; baseline and differential.
DR   GO; GO:0005737; C:cytoplasm; IBA:GO_Central.
DR   GO; GO:0005739; C:mitochondrion; IEA:UniProtKB-SubCell.
DR   GO; GO:0004124; F:cysteine synthase activity; IDA:UniProtKB.
DR   GO; GO:0050017; F:L-3-cyanoalanine synthase activity; IDA:UniProtKB.
DR   GO; GO:0019499; P:cyanide metabolic process; IDA:UniProtKB.
DR   GO; GO:0019344; P:cysteine biosynthetic process; IBA:GO_Central.
DR   GO; GO:0006535; P:cysteine biosynthetic process from serine; IBA:GO_Central.
DR   GO; GO:0006534; P:cysteine metabolic process; IDA:UniProtKB.
DR   Gene3D; 3.40.50.1100; -; 2.
DR   InterPro; IPR031111; CAS.
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   PANTHER; PTHR10314:SF80; PTHR10314:SF80; 1.
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   1: Evidence at protein level;
KW   Amino-acid biosynthesis; Cysteine biosynthesis; Direct protein sequencing;
KW   Lyase; Mitochondrion; Pyridoxal phosphate; Reference proteome; Transferase;
KW   Transit peptide.
FT   TRANSIT         1..10
FT                   /note="Mitochondrion"
FT                   /evidence="ECO:0000255"
FT   CHAIN           11..351
FT                   /note="Bifunctional L-3-cyanoalanine synthase/cysteine
FT                   synthase 1, mitochondrial"
FT                   /id="PRO_0000418637"
FT   BINDING         104
FT                   /ligand="pyridoxal 5'-phosphate"
FT                   /ligand_id="ChEBI:CHEBI:597326"
FT                   /evidence="ECO:0000250"
FT   BINDING         208..212
FT                   /ligand="pyridoxal 5'-phosphate"
FT                   /ligand_id="ChEBI:CHEBI:597326"
FT                   /evidence="ECO:0000250"
FT   BINDING         296
FT                   /ligand="pyridoxal 5'-phosphate"
FT                   /ligand_id="ChEBI:CHEBI:597326"
FT                   /evidence="ECO:0000250"
FT   MOD_RES         73
FT                   /note="N6-(pyridoxal phosphate)lysine"
FT                   /evidence="ECO:0000250"
FT   CONFLICT        322
FT                   /note="H -> W (in Ref. 2; AA sequence)"
FT                   /evidence="ECO:0000305"
SQ   SEQUENCE   351 AA;  38201 MW;  F1CC41CBC57E7D37 CRC64;
     MASLLRRRFY SSESSFAQRL RDLPKYLPGT NIKTQVSQLI GKTPLVYLNK VSEGCGAYIA
     VKQEMMQPTS SIKDRPAFAM INDAEKKGLI TPGKTTLIEP TSGNMGISMA FMAAMKGYKM
     ILTMPSYTSL ERRVTMRAFG ADLVTTDPTK GMGGTIKKAY DLLESTPNAY MLQQFSNPAN
     TQAHFETTGP EIWEDTQGNV DIFVMGIGSG GTVSGVGQYL KSKNPNVKIY GIEPTESNVL
     NGGNPGPHEI TGNGVGFKPD ILDMDVMEEV LMVSSEESVN MARELALKEG LMVGISSGAN
     TVAALRLANR PENKGKLIVT IHPSFGERYL SSVLYEDIRK EAQNMQPVSV D