CYSC_SPIOL
ID CYSC_SPIOL Reviewed; 368 AA.
AC Q43153;
DT 05-SEP-2012, integrated into UniProtKB/Swiss-Prot.
DT 01-NOV-1996, sequence version 1.
DT 03-AUG-2022, entry version 100.
DE RecName: Full=Bifunctional L-3-cyanoalanine synthase/cysteine synthase, mitochondrial;
DE EC=2.5.1.47 {ECO:0000269|PubMed:10889265, ECO:0000269|PubMed:10948226, ECO:0000269|PubMed:7961755};
DE EC=4.4.1.9 {ECO:0000269|PubMed:10889265, ECO:0000269|PubMed:10948226};
DE AltName: Full=Beta-cyanoalanine synthase;
DE Short=SoCAS;
DE AltName: Full=Beta-substituted Ala synthase 3-1;
DE Short=SPIol-Bsas3-1;
DE AltName: Full=Cysteine synthase C;
DE Flags: Precursor;
GN Name=CYSC; Synonyms=CAS, CSase C;
OS Spinacia oleracea (Spinach).
OC Eukaryota; Viridiplantae; Streptophyta; Embryophyta; Tracheophyta;
OC Spermatophyta; Magnoliopsida; eudicotyledons; Gunneridae; Pentapetalae;
OC Caryophyllales; Chenopodiaceae; Chenopodioideae; Anserineae; Spinacia.
OX NCBI_TaxID=3562;
RN [1]
RP NUCLEOTIDE SEQUENCE [MRNA], FUNCTION, CATALYTIC ACTIVITY, AND TISSUE
RP SPECIFICITY.
RX PubMed=7961755; DOI=10.1016/s0021-9258(18)46912-8;
RA Saito K., Tatsuguchi K., Takagi Y., Murakoshi I.;
RT "Isolation and characterization of cDNA that encodes a putative
RT mitochondrion-localizing isoform of cysteine synthase (O-
RT acetylserine(thiol)-lyase) from Spinacia oleracea.";
RL J. Biol. Chem. 269:28187-28192(1994).
RN [2]
RP NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RA Noda M., Nakamura M., Takamiya R., Tamura T., Ito T., Kodama H.;
RT "Inhibition of cysteine synthase activity in the transgenic tobacco plants
RT expressing a spinach cysteine synthase-like protein.";
RL Submitted (MAR-2008) to the EMBL/GenBank/DDBJ databases.
RN [3]
RP PROTEIN SEQUENCE OF 28-39, CATALYTIC ACTIVITY, AND BIOPHYSICOCHEMICAL
RP PROPERTIES.
RC STRAIN=cv. Medina;
RX PubMed=10948226; DOI=10.1093/jexbot/51.347.985;
RA Warrilow A.G., Hawkesford M.J.;
RT "Cysteine synthase (O-acetylserine (thiol) lyase) substrate specificities
RT classify the mitochondrial isoform as a cyanoalanine synthase.";
RL J. Exp. Bot. 51:985-993(2000).
RN [4]
RP FUNCTION, CATALYTIC ACTIVITY, AND BIOPHYSICOCHEMICAL PROPERTIES.
RX PubMed=10889265; DOI=10.1104/pp.123.3.1163;
RA Hatzfeld Y., Maruyama A., Schmidt A., Noji M., Ishizawa K., Saito K.;
RT "beta-Cyanoalanine synthase is a mitochondrial cysteine synthase-like
RT protein in spinach and Arabidopsis.";
RL Plant Physiol. 123:1163-1171(2000).
CC -!- FUNCTION: The cyanoalanine synthesis reaction is more efficient than
CC the cysteine synthase activity. Probably involved in the detoxification
CC of cyanide that arises from ethylene biosynthesis.
CC {ECO:0000269|PubMed:10889265, ECO:0000269|PubMed:7961755}.
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:10889265, ECO:0000269|PubMed:10948226,
CC ECO:0000269|PubMed:7961755};
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:10889265,
CC ECO:0000269|PubMed:10948226};
CC -!- COFACTOR:
CC Name=pyridoxal 5'-phosphate; Xref=ChEBI:CHEBI:597326;
CC Evidence={ECO:0000305};
CC -!- BIOPHYSICOCHEMICAL PROPERTIES:
CC Kinetic parameters:
CC KM=14.48 mM for O(3)-acetyl-L-serine for the cysteine synthase
CC activity with the recombinant enzyme {ECO:0000269|PubMed:10889265,
CC ECO:0000269|PubMed:10948226};
CC KM=3.57 mM for Na(2)S for the cysteine synthase activity with the
CC recombinant enzyme {ECO:0000269|PubMed:10889265,
CC ECO:0000269|PubMed:10948226};
CC KM=2.14 mM for L-cysteine for the L-3-cyanoalanine synthase activity
CC with the recombinant enzyme {ECO:0000269|PubMed:10889265,
CC ECO:0000269|PubMed:10948226};
CC KM=0.10 mM for KCN for the L-3-cyanoalanine synthase activity with
CC the recombinant enzyme {ECO:0000269|PubMed:10889265,
CC ECO:0000269|PubMed:10948226};
CC KM=0.409 mM for L-cysteine for the L-3-cyanoalanine synthase activity
CC with the native enzyme {ECO:0000269|PubMed:10889265,
CC ECO:0000269|PubMed:10948226};
CC KM=9.728 mM for O(3)-acetyl-L-serine for the cysteine synthase
CC activity with the native enzyme {ECO:0000269|PubMed:10889265,
CC ECO:0000269|PubMed:10948226};
CC KM=0.595 mM for chloroalanine for the cysteine synthase activity with
CC the native enzyme (at pH 8.0) {ECO:0000269|PubMed:10889265,
CC ECO:0000269|PubMed:10948226};
CC KM=0.464 mM for chloroalanine for the cysteine synthase activity with
CC the native enzyme (at pH 9.8) {ECO:0000269|PubMed:10889265,
CC ECO:0000269|PubMed:10948226};
CC pH dependence:
CC Optimum pH is 10.0. {ECO:0000269|PubMed:10889265,
CC ECO:0000269|PubMed:10948226};
CC -!- SUBCELLULAR LOCATION: Mitochondrion {ECO:0000305}.
CC -!- TISSUE SPECIFICITY: Expressed in green and etiolated seedlings.
CC {ECO:0000269|PubMed:7961755}.
CC -!- SIMILARITY: Belongs to the cysteine synthase/cystathionine beta-
CC synthase family. {ECO:0000305}.
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DR EMBL; D37963; BAA07177.1; -; mRNA.
DR EMBL; AB426589; BAG72099.1; -; Genomic_DNA.
DR PIR; A55450; A55450.
DR AlphaFoldDB; Q43153; -.
DR SMR; Q43153; -.
DR IntAct; Q43153; 1.
DR OrthoDB; 1016546at2759; -.
DR BRENDA; 4.4.1.9; 5812.
DR SABIO-RK; Q43153; -.
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:0006535; P:cysteine biosynthetic process from serine; IEA:InterPro.
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; Transferase; Transit peptide.
FT TRANSIT 1..27
FT /note="Mitochondrion"
FT /evidence="ECO:0000269|PubMed:10948226"
FT CHAIN 28..368
FT /note="Bifunctional L-3-cyanoalanine synthase/cysteine
FT synthase, mitochondrial"
FT /id="PRO_0000418636"
FT BINDING 121
FT /ligand="pyridoxal 5'-phosphate"
FT /ligand_id="ChEBI:CHEBI:597326"
FT /evidence="ECO:0000250"
FT BINDING 225..229
FT /ligand="pyridoxal 5'-phosphate"
FT /ligand_id="ChEBI:CHEBI:597326"
FT /evidence="ECO:0000250"
FT BINDING 313
FT /ligand="pyridoxal 5'-phosphate"
FT /ligand_id="ChEBI:CHEBI:597326"
FT /evidence="ECO:0000250"
FT MOD_RES 90
FT /note="N6-(pyridoxal phosphate)lysine"
FT /evidence="ECO:0000250"
SQ SEQUENCE 368 AA; 39510 MW; FA985E1FE35CF0DE CRC64;
MATVSSCLLR RSRTASRIFK TSLRCFSTTS SSAQTVSGSS PFPFTGTNIK TNVSQLIGRT
PLVYLSKISE GSGAYIAVKQ EMMQPTASVK DRPALAMIED AEKKGLISPG KTVLIEPTSG
NMGISMAFMA AMKGYKMVLT MPSYTSMERR VVMRAFGADL ILTDPDKGMG GTVKKANQLL
DSTPDGFMLQ QFNNPANTQV HFETTGPEIW EDTQGKVDIF VMGIGSGGTV SGVGRYLKSQ
NPNVKIYGVE PAESNILNGG KPGPHLITGN GVGFKPEILD MDVMDAVLEV KSDDAVKMAR
QLALQEGLLV GISSGANTIA ALDLAKRPEN KGKLIVTIHP SFGERYLSSA LFKELREEAE
NMQPVPVE
