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.

Copyright

Copyrighted by the UniProt Consortium, see http://www.uniprot.org/terms. Distributed under the Creative Commons Attribution-NoDerivs License.

Cross-references

Sequence databases

EMBL

CP000789; ABU69064.1; -; Genomic_DNA.

[EMBL / GenBank / DDBJ] [CoDingSequence]

RefSeq

YP_001443291.1; -.

3D structure databases

ModBase

A7MSZ7.

Ontologies

GO:0005506;	Molecular function: iron ion binding (inferred from electronic annotation from UniProtKB-KW).
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.

PR00397; SIROHAEM.

TIGR02041; CysI; 1.

PS00365; NIR_SIR; 1.

Genome annotation databases

GeneID

5553777; -.

GenomeReviews

CP000789_GR; VIBHAR_00004.

KEGG

vha:VIBHAR_00004; -.

NMPDR

fig|338187.4.peg.47; -.

CMR

A7MSZ7; VIBHAR_00004.

Other

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`	`1 578`	`578`	`Sulfite reductase [NADPH] hemoprotein beta-component.`	`PRO_1000068779`
`METAL`	`441 441`		`Iron-sulfur (4Fe-4S) (By similarity).`
`METAL`	`447 447`		`Iron-sulfur (4Fe-4S) (By similarity).`
`METAL`	`487 487`		`Iron-sulfur (4Fe-4S) (By similarity).`
`METAL`	`491 491`		`Iron (siroheme axial ligand) (By similarity).`
`METAL`	`491 491`		`Iron-sulfur (4Fe-4S) (By similarity).`

Sequence information

Length: 578 AA [This is the length of the unprocessed precursor]

Molecular weight: 64673 Da [This is the MW of the unprocessed precursor]

CRC64: 7CFB712145E9A2BD [This is a checksum on the sequence]

        10         20         30         40         50         60 
MSANQQSNSQ EVLGEVLGPL SDNERLKRES NLLRGTIEQD LQDRITGGFT ADNFQLIRFH 

        70         80         90        100        110        120 
GMYQQDDRDI RNERAKQKLE PLHNVMLRAR MPGGIITPKQ WLAIDKFATE HSLYGSIRLT 

       130        140        150        160        170        180 
TRQTFQFHGV LKPNIKLMHQ TLNSIGIDSI ATAGDVNRNV LCTTNPVESE LHQEAYEWAK 

       190        200        210        220        230        240 
KISEHLLPKT RAYAEIWLDG EKVESTEEDE PILGKNYLPR KFKTTVVIPP QNDVDVHAND 

       250        260        270        280        290        300 
LNFVAIADNG KLVGFNVLVG GGLAMTHCDT STYPRRADDF GFIPLEKTLD VAAAVVTTQR 

       310        320        330        340        350        360 
DWGNRSNRKN AKTKYTLDRV GSDVFKAEVE KRAGVKFEQS RPYEFTERGD RIGWVEGIDG 

       370        380        390        400        410        420 
KHHLALFIEN GRLLDFPGKP LKTGVAEIAK IHKGDFRMTA NQNLIVAGVP KSQKAKIEKI 

       430        440        450        460        470        480 
AREHGLMDDG VSEQRKNSMA CVAFPTCPLA MAEAERFLPQ FVTDVEGILE KHGIPEEDNI 

       490        500        510        520        530        540 
ILRVTGCPNG CGRAMLAEIG LVGKAPGRYN LHLGGNRGGT RVPKMCKENI TDKQILEEID 

       550        560        570 
QLVARWAAER EEGEAFGDFT IRAGIIQEVF VSKRDFHA

A7MSZ7 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