UniProt functional annotation for Q9Z4P4

UniProt code: Q9Z4P4.

Organism:		Sulfurospirillum deleyianum.
Taxonomy:		Bacteria; Proteobacteria; Epsilonproteobacteria; Campylobacterales; Campylobacteraceae; Sulfurospirillum.
Function:		Catalyzes the reduction of nitrite to ammonia, consuming six electrons in the process (PubMed:7999130). Has very low activity toward hydroxylamine, and even lower activity toward sulfite. Sulfite reductase activity is maximal at neutral pH (By similarity). {ECO:0000250|UniProtKB:L0DSL2, ECO:0000269|PubMed:7999130}.
Catalytic activity:		Reaction=6 [Fe(III)cytochrome c] + 2 H2O + NH4(+) = 6 [Fe(II)cytochrome c] + 8 H(+) + nitrite; Xref=Rhea:RHEA:13089, Rhea:RHEA-COMP:10350, Rhea:RHEA-COMP:14399, ChEBI:CHEBI:15377, ChEBI:CHEBI:15378, ChEBI:CHEBI:16301, ChEBI:CHEBI:28938, ChEBI:CHEBI:29033, ChEBI:CHEBI:29034; EC=1.7.2.2; Evidence={ECO:0000269|PubMed:7999130};
Cofactor:		Name=Ca(2+); Xref=ChEBI:CHEBI:29108; Note=Binds 1 Ca(2+) ion per monomer. {ECO:0000269|PubMed:10440380};
Cofactor:		Name=heme; Xref=ChEBI:CHEBI:30413; Evidence={ECO:0000269|PubMed:10440380, ECO:0000269|PubMed:7999130}; Note=Binds 5 heme groups covalently per monomer. {ECO:0000269|PubMed:10440380};
Pathway:		Nitrogen metabolism; nitrate reduction (assimilation). {ECO:0000305|PubMed:7999130}.
Subunit:		Homodimer (PubMed:7999130). Probably also exists as a membrane-associated heterooligomeric complex (PubMed:10440380). {ECO:0000269|PubMed:10440380, ECO:0000269|PubMed:7999130}.
Subcellular location:		Periplasm {ECO:0000305|PubMed:7999130}.
Miscellaneous:		X-ray crystallographic analysis includes a sulfate ion that is thought to be at the substrate-binding site. {ECO:0000269|PubMed:10440380}.
Similarity:		Belongs to the cytochrome c-552 family. {ECO:0000305}.
Sequence caution:		Sequence=CAB37320.2; Type=Erroneous initiation; Evidence={ECO:0000305};

Annotations taken from UniProtKB at the EBI.