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HAMAP rule MF_01540

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General rule information [?]

Accession MF_01540
Dates 22-AUG-2005 (Created)
1-JUN-2023 (Last updated, Version 16)
Name CysI
Scope
Bacteria
Templates P17846 (CYSI_ECOLI); P17845 (CYSI_SALTY); O32213 (CYSI_BACSU); Q8KQT8 (CYSI_XANOR): [Recover all]

Propagated annotation [?]


Identifier, protein and gene names [?]

Identifier
CYSI
Protein name
RecName: Full=Sulfite reductase [NADPH] hemoprotein beta-component;
Short=SiR-HP;
Short=SiRHP;
EC 1.8.1.2;
Gene name
cysI

Comments [?]

Function Component of the sulfite reductase complex that catalyzes the 6-electron reduction of sulfite to sulfide. This is one of several activities required for the biosynthesis of L-cysteine from sulfate.
Catalytic activity RHEA:13801: 3 H2O + hydrogen sulfide + 3 NADP(+) = 4 H(+) + 3 NADPH + sulfite
EC 1.8.1.2
Cofactor siroheme
Note: Binds 1 siroheme per subunit.
[4Fe-4S] cluster
Note: Binds 1 [4Fe-4S] cluster per subunit.
Pathway Sulfur metabolism; hydrogen sulfide biosynthesis; hydrogen sulfide from sulfite (NADPH route): step 1/1.
Subunit Alpha(8)-beta(8). The alpha component is a flavoprotein, the beta component is a hemoprotein.
Similarity Belongs to the nitrite and sulfite reductase 4Fe-4S domain family.

Keywords [?]


Gene Ontology [?]

GO:0004783; Molecular function: sulfite reductase (NADPH) activity.
GO:0000103; Biological process: sulfate assimilation.
GO:0070814; Biological process: hydrogen sulfide biosynthetic process.

Cross-references [?]

PROSITE PS00365; NIR_SIR; 1;
Pfam PF01077; NIR_SIR; 1;
PF03460; NIR_SIR_ferr; 2;
PRINTS PR00397; SIROHAEM; 1;
NCBIfam TIGR02041; CysI; 1;

Features [?]

From: CYSI_ECOLI (P17846)
Key     From     To       Description   Tag   Condition   FTGroup
BINDING     434     434       /ligand="[4Fe-4S] cluster" /ligand_id="ChEBI:CHEBI:49883     C  
BINDING     440     440       /ligand="[4Fe-4S] cluster" /ligand_id="ChEBI:CHEBI:49883     C  
BINDING     479     479       /ligand="[4Fe-4S] cluster" /ligand_id="ChEBI:CHEBI:49883     C  
BINDING     483     483       /ligand="siroheme" /ligand_id="ChEBI:CHEBI:60052" /ligand_part="Fe" /ligand_part_id="ChEBI:CHEBI:18248" /note="axial binding residue     C  
BINDING     483     483       /ligand="[4Fe-4S] cluster" /ligand_id="ChEBI:CHEBI:49883     C  

Additional information [?]

Size range 555-616 amino acids
Related rules None
Fusion None