P0A1E3 · CYSK_SALTY

Function

function

Two cysteine synthase enzymes are found, this enzyme and CysM; both catalyze the same reaction. Cysteine synthase B (CysM) can also use thiosulfate in place of sulfide to give cysteine thiosulfonate as a product.

Catalytic activity

Cofactor

pyridoxal 5'-phosphate (UniProtKB | Rhea| CHEBI:597326 )

Activity regulation

O-acetyl-L-serine causes the CysE-CysK complex to dissociate in the absence of hydrogen sulfide.

Kinetics

KM SUBSTRATE pH TEMPERATURE[C] NOTES EVIDENCE
5 mMO-acetyl-L-serine as isolated subunit and in complex with CysK

Pathway

Amino-acid biosynthesis; L-cysteine biosynthesis; L-cysteine from L-serine: step 2/2.

Features

Showing features for binding site.

TypeIDPosition(s)Description
Binding site8hydrogen sulfide (UniProtKB | ChEBI); allosteric inhibitor; ligand shared between dimeric partners
Binding site35hydrogen sulfide (UniProtKB | ChEBI); allosteric inhibitor; ligand shared between dimeric partners; in other chain
Binding site72pyridoxal 5'-phosphate (UniProtKB | ChEBI)
Binding site177-181pyridoxal 5'-phosphate (UniProtKB | ChEBI)
Binding site269hydrogen sulfide (UniProtKB | ChEBI); allosteric inhibitor; ligand shared between dimeric partners; in other chain
Binding site273pyridoxal 5'-phosphate (UniProtKB | ChEBI)

GO annotations

AspectTerm
Cellular Componentcytoplasm
Molecular Functioncysteine synthase activity
Molecular FunctionL-cysteine desulfhydrase activity
Biological Processcysteine biosynthetic process from serine

Keywords

Enzyme and pathway databases

Names & Taxonomy

Protein names

  • Recommended name
    Cysteine synthase A
  • EC number
  • Short names
    CSase A
  • Alternative names
    • O-acetylserine (thiol)-lyase A
      (OAS-TL A)
    • O-acetylserine sulfhydrylase A

Gene names

    • Name
      cysK
    • Ordered locus names
      STM2430

Organism names

Accessions

  • Primary accession
    P0A1E3
  • Secondary accessions
    • P12674

Proteomes

Subcellular Location

PTM/Processing

Features

Showing features for initiator methionine, chain, modified residue.

TypeIDPosition(s)Description
Initiator methionine1Removed
ChainPRO_00001670892-323Cysteine synthase A
Modified residue42N6-(pyridoxal phosphate)lysine

Proteomic databases

Interaction

Subunit

Part of the cysteine synthase complex formed at a ratio of 2 copies of this protein and 1 copy of serine acetyltransferase (cysE). The complex reversibly dissociates in the presence of O-acetyl-L-serine but in the absence of hydrogen sulfide (PubMed:4977445).
Homodimer (PubMed:10452898, PubMed:11023792, PubMed:9761678).

Protein-protein interaction databases

Family & Domains

Sequence similarities

Phylogenomic databases

Family and domain databases

Sequence

  • Sequence status
    Complete
  • Length
    323
  • Mass (Da)
    34,536
  • Last updated
    2007-01-23 v2
  • Checksum
    CE74168FAAE99B9E
MSKIYEDNSLTIGHTPLVRLNRIGNGRILAKVESRNPSFSVKCRIGANMIWDAEKRGVLKPGVELVEPTSGNTGIALAYVAAARGYKLTLTMPETMSIERRKLLKALGANLVLTEGAKGMKGAIQKAEEIVASDPQKYLLLQQFSNPANPEIHEKTTGPEIWEDTDGQVDVFISGVGTGGTLTGVTRYIKGTKGKTDLITVAVEPTDSPVIAQALAGEEIKPGPHKIQGIGAGFIPGNLDLKLIDKVVGITNEEAISTARRLMEEEGILAGISSGAAVAAALKLQEDESFTNKNIVVILPSSGERYLSTALFADLFTEKELQQ

Features

Showing features for sequence conflict.

TypeIDPosition(s)Description
Sequence conflict70in Ref. 1; AAA27051
Sequence conflict267-268in Ref. 1; AAA27051

Keywords

Sequence databases

Nucleotide SequenceProtein SequenceMolecule TypeStatus
M21450
EMBL· GenBank· DDBJ
AAA27051.1
EMBL· GenBank· DDBJ
Genomic DNA
AE006468
EMBL· GenBank· DDBJ
AAL21324.1
EMBL· GenBank· DDBJ
Genomic DNA

Genome annotation databases

Similar Proteins

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