P0A1E3 · CYSK_SALTY
- ProteinCysteine synthase A
- GenecysK
- StatusUniProtKB reviewed (Swiss-Prot)
- Amino acids323 (go to sequence)
- Protein existenceEvidence at protein level
- Annotation score5/5
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
- O-acetyl-L-serine + hydrogen sulfide = L-cysteine + acetate
Cofactor
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 mM | O-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.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Binding site | 8 | hydrogen sulfide (UniProtKB | ChEBI); allosteric inhibitor; ligand shared between dimeric partners | ||||
Sequence: N | ||||||
Binding site | 35 | hydrogen sulfide (UniProtKB | ChEBI); allosteric inhibitor; ligand shared between dimeric partners; in other chain | ||||
Sequence: R | ||||||
Binding site | 72 | pyridoxal 5'-phosphate (UniProtKB | ChEBI) | ||||
Sequence: N | ||||||
Binding site | 177-181 | pyridoxal 5'-phosphate (UniProtKB | ChEBI) | ||||
Sequence: GTGGT | ||||||
Binding site | 269 | hydrogen sulfide (UniProtKB | ChEBI); allosteric inhibitor; ligand shared between dimeric partners; in other chain | ||||
Sequence: L | ||||||
Binding site | 273 | pyridoxal 5'-phosphate (UniProtKB | ChEBI) | ||||
Sequence: S |
GO annotations
Aspect | Term | |
---|---|---|
Cellular Component | cytoplasm | |
Molecular Function | cysteine synthase activity | |
Molecular Function | L-cysteine desulfhydrase activity | |
Biological Process | cysteine biosynthetic process from serine |
Keywords
- Molecular function
- Biological process
- Ligand
Enzyme and pathway databases
Names & Taxonomy
Protein names
- Recommended nameCysteine synthase A
- EC number
- Short namesCSase A
- Alternative names
Gene names
Organism names
- Strains
- Taxonomic lineageBacteria > Pseudomonadota > Gammaproteobacteria > Enterobacterales > Enterobacteriaceae > Salmonella
Accessions
- Primary accessionP0A1E3
- Secondary accessions
Proteomes
Subcellular Location
UniProt Annotation
GO Annotation
PTM/Processing
Features
Showing features for initiator methionine, chain, modified residue.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Initiator methionine | 1 | Removed | ||||
Sequence: M | ||||||
Chain | PRO_0000167089 | 2-323 | Cysteine synthase A | |||
Sequence: SKIYEDNSLTIGHTPLVRLNRIGNGRILAKVESRNPSFSVKCRIGANMIWDAEKRGVLKPGVELVEPTSGNTGIALAYVAAARGYKLTLTMPETMSIERRKLLKALGANLVLTEGAKGMKGAIQKAEEIVASDPQKYLLLQQFSNPANPEIHEKTTGPEIWEDTDGQVDVFISGVGTGGTLTGVTRYIKGTKGKTDLITVAVEPTDSPVIAQALAGEEIKPGPHKIQGIGAGFIPGNLDLKLIDKVVGITNEEAISTARRLMEEEGILAGISSGAAVAAALKLQEDESFTNKNIVVILPSSGERYLSTALFADLFTEKELQQ | ||||||
Modified residue | 42 | N6-(pyridoxal phosphate)lysine | ||||
Sequence: K |
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).
Homodimer (PubMed:10452898, PubMed:11023792, PubMed:9761678).
Protein-protein interaction databases
Structure
Sequence
- Sequence statusComplete
- Length323
- Mass (Da)34,536
- Last updated2007-01-23 v2
- ChecksumCE74168FAAE99B9E
Features
Showing features for sequence conflict.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Sequence conflict | 70 | in Ref. 1; AAA27051 | ||||
Sequence: S → N | ||||||
Sequence conflict | 267-268 | in Ref. 1; AAA27051 | ||||
Sequence: GI → VF |
Keywords
- Technical term
Sequence databases
Nucleotide Sequence | Protein Sequence | Molecule Type | Status | |
---|---|---|---|---|
M21450 EMBL· GenBank· DDBJ | AAA27051.1 EMBL· GenBank· DDBJ | Genomic DNA | ||
AE006468 EMBL· GenBank· DDBJ | AAL21324.1 EMBL· GenBank· DDBJ | Genomic DNA |