FUNCTION: This enzyme catalyzes the 6-electron reduction of sulfite to sulfide. This is one of several activities required for the biosynthesis of L-cysteine from sulfate (By similarity).
CATALYTIC ACTIVITY: H₂S + 3 NADP⁺ + 3 H₂O = sulfite + 3 NADPH.
COFACTOR: Binds 1 siroheme per subunit (By similarity).
COFACTOR: Binds 1 4Fe-4S cluster per subunit (By similarity).
SUBUNIT: Alpha(8)-beta(4). The alpha component is a flavoprotein, the beta component is a hemoprotein (By similarity).
SIMILARITY: Belongs to the nitrite and sulfite reductase 4Fe-4S domain family.
CAUTION: Could be the product of a pseudogene.
SEQUENCE CAUTION:
- Sequence=AE013218; Type=Frameshift; Positions=170;

Copyright

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Cross-references

Sequence databases

EMBL

AE013218; -; NOT_ANNOTATED_CDS; Genomic_DNA.

[EMBL / GenBank / DDBJ]

3D structure databases

ModBase

P0C0B2.

Ontologies

GO:0009337;	Cellular component: sulfite reductase complex (NADPH) (inferred from electronic annotation from InterPro).
GO:0051539;	Molecular function: 4 iron, 4 sulfur cluster binding (inferred from electronic annotation from InterPro).
GO:0009055;	Molecular function: electron carrier activity (inferred from electronic annotation from InterPro).
GO:0020037;	Molecular function: heme binding (inferred from electronic annotation from InterPro).
GO:0005506;	Molecular function: iron ion binding (inferred from electronic annotation from UniProtKB-KW).
GO:0050661;	Molecular function: NADP binding (inferred from electronic annotation from InterPro).
GO:0004783;	Molecular function: sulfite reductase (NADPH) activity (inferred from electronic annotation from HAMAP).
GO:0019344;	Biological process: cysteine biosynthetic process (inferred from electronic annotation from UniProtKB-KW).
GO:0055114;	Biological process: oxidation reduction (inferred from electronic annotation from UniProtKB-KW).
GO:0000103;	Biological process: sulfate assimilation (inferred from electronic annotation from HAMAP).
QuickGo view.

Family and domain databases

HAMAP

MF_01540; -; 1.
PBIL [Tree]

InterPro

IPR011786; CysI.
IPR006066; Nir_Si_BS.
IPR006067; Nir_Sir_4Fe4S.
IPR005117; NiRdtase/SiRdtase_haem-b_fer.
Graphical view of domain structure.

Pfam

PF01077; NIR_SIR; 1.
PF03460; NIR_SIR_ferr; 2.
Pfam graphical view of domain structure.

PRINTS

PR00397; SIROHAEM.

TIGRFAMs

TIGR02041; CysI; 1.

PROSITE

PS00365; NIR_SIR; 1.

Genome annotation databases

GenomeReviews

AE013218_GR; BUsg_412.

KEGG

bas:BUsg412; -.

Phylogenomic databases

HOGENOM

P0C0B2; -.

Genome annotation databases

CMR

P0C0B2; BUsg_412.

Other

ProtoNet

P0C0B2.

UniRef

View cluster of proteins with at least 50% / 90% / 100% identity.

Keywords

4Fe-4S; Amino-acid biosynthesis; Complete proteome; Cysteine biosynthesis; Heme; Iron; Iron-sulfur; Metal-binding; NADP; Oxidoreductase.

Features

Feature table viewer

`Key`	`From To`	`Length`	`Description`	`FTId`
`CHAIN`	`1 566`	`566`	`Putative sulfite reductase [NADPH] hemoprotein beta-component.`	`PRO_0000199894`
`METAL`	`430 430`		`Iron-sulfur (4Fe-4S) (By similarity).`
`METAL`	`436 436`		`Iron-sulfur (4Fe-4S) (By similarity).`
`METAL`	`475 475`		`Iron-sulfur (4Fe-4S) (By similarity).`
`METAL`	`479 479`		`Iron (siroheme axial ligand) (By similarity).`
`METAL`	`479 479`		`Iron-sulfur (4Fe-4S) (By similarity).`

Sequence information

Length: 566 AA [This is the length of the unprocessed precursor]

Molecular weight: 65353 Da [This is the MW of the unprocessed precursor]

CRC64: E6F10AF8BC27F19C [This is a checksum on the sequence]

        10         20         30         40         50         60 
MKKDYKKVFL KNTKEERIKE NSNYLRGTII DDLKDEITNG FTGDNFSLIR FHGMYQDDRD 

        70         80         90        100        110        120 
LRLERNEQKL EPRYAMMLRC RLPRGIIKAK KWLKIDHFAS KNTLYGTIRL NNLQTFQFHG 

       130        140        150        160        170        180 
ILKKTLKDAH KMLNKIGLDS LGTANDVNRN VLCTSNPMES LIHQQCYEWV SKISNFLLPQ 

       190        200        210        220        230        240 
TKAYAEIWLN QKKIATTDQE PILGKTYLPR KFKTTVVVPP YNDVDLYAND MNFIAITKNN 

       250        260        270        280        290        300 
KIVGFNVLIG GGLSINHGNK NTWPFLAVEL GYITLEKTLS VAESIVTTQR DWGNRTDRKN 

       310        320        330        340        350        360 
AKTRYTIAKV GLSVFKKEVE KRANMTFETI KPYYFISRGD RFGWTKNINN DWSLTVFIQN 

       370        380        390        400        410        420 
GRIYDNDKQL VKSGLLKIAN LHTGNFRLTA NQNIVISEIL DKNKKKIEEI AISHGLIKKV 

       430        440        450        460        470        480 
SSLRENSMAC VSFPTCPLAI AESERILSFF ITKVENIMLK YGIEKEIIIL RISGCPNGCG 

       490        500        510        520        530        540 
RSLLAEIGLI GKSLGRYNLY IGGNRIGSRI PKIYKENITE QEILIHLDFL IKIWSIERQK 

       550        560 
KEHFGDFVIR RNVVKKVVNP IYDFWN

P0C0B2 in FASTA format

View entry in original UniProtKB/Swiss-Prot format
View entry in raw text format (no links)
Report form for errors/updates in this UniProtKB/Swiss-Prot entry

	BLAST submission on ExPASy/SIB or at NCBI (USA)		Sequence analysis tools: ProtParam, ProtScale, Compute pI/Mw, PeptideMass, PeptideCutter, Dotlet (Java)
	ScanProsite, MotifScan		Submit a homology modeling request to SWISS-MODEL
	NPSA Sequence analysis tools