FUNCTION: Catalyzes the 6-electron reduction of sulfite to sulfide. This is one of several activities required for the biosynthesis of L-cysteine from sulfate. The flavo-protein component catalyzes the electron flow from NADPH -> FAD -> FMN to the hemoprotein component (By similarity).
CATALYTIC ACTIVITY: H₂S + 3 NADP⁺ + 3 H₂O = sulfite + 3 NADPH.
COFACTOR: Binds 1 FAD per subunit (By similarity).
COFACTOR: Binds 1 FMN per subunit (By similarity).
SUBUNIT: Alpha(8)-beta(8). The alpha component is a flavoprotein, the beta component is a hemoprotein (By similarity).
SIMILARITY: Contains 1 FAD-binding FR-type domain.
SIMILARITY: Contains 1 flavodoxin-like domain.

Copyright

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Cross-references

Sequence databases

EMBL

CP000946; ACA76617.1; -; Genomic_DNA.

[EMBL / GenBank / DDBJ] [CoDingSequence]

RefSeq

YP_001723944.1; -.

3D structure databases

ModBase

B1IU77.

Ontologies

GO:0009055;	Molecular function: electron carrier activity (inferred from electronic annotation from InterPro).
GO:0010181;	Molecular function: FMN binding (inferred from electronic annotation from InterPro).
GO:0005506;	Molecular function: iron ion 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 InterPro).
GO:0022900;	Biological process: electron transport chain (inferred from electronic annotation from UniProtKB-KW).
GO:0000103;	Biological process: sulfate assimilation (inferred from electronic annotation from HAMAP).
GO:0006810;	Biological process: transport (inferred from electronic annotation from UniProtKB-KW).
QuickGo view.

Family and domain databases

HAMAP

MF_01541; -; 1.
PBIL [Tree]

InterPro

IPR010199; CysJ.
IPR003097; FAD-binding_1.
IPR001094; Flavdoxin_like.
IPR008254; Flavodoxin/NO_synth.
IPR001709; FPN_cyt_redctse.
IPR001433; OxRdtase_FAD/NAD_bd.
Graphical view of domain structure.

Pfam

PF00667; FAD_binding_1; 1.
PF00258; Flavodoxin_1; 1.
PF00175; NAD_binding_1; 1.
Pfam graphical view of domain structure.

PROSITE

PS51384; FAD_FR; 1.
PS50902; FLAVODOXIN_LIKE; 1.
PROSITE graphical view of domain structure (profiles).

ProtoNet

B1IU77.

Genome annotation databases

GeneID

6068352; -.

GenomeReviews

CP000946_GR; EcolC_0948.

KEGG

ecl:EcolC_0948; -.

CMR

B1IU77; EcolC_0948.

Other

UniRef

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

Keywords

Amino-acid biosynthesis; Complete proteome; Cysteine biosynthesis; Electron transport; FAD; Flavoprotein; FMN; NADP; Oxidoreductase; Transport.

Features

Feature table viewer

Feature aligner

`Key`	`From To`	`Length`	`Description`	`FTId`
`CHAIN`	`1 599`	`599`	`Sulfite reductase [NADPH] flavoprotein alpha-component.`	`PRO_1000087634`
`DOMAIN`	`64 202`	`139`	`Flavodoxin-like.`
`DOMAIN`	`234 448`	`215`	`FAD-binding FR-type.`
`NP_BIND`	`70 74`	`5`	`FMN (By similarity).`
`NP_BIND`	`150 181`	`32`	`FMN (By similarity).`
`NP_BIND`	`236 288`	`53`	`FAD (By similarity).`
`NP_BIND`	`472 599`	`128`	`NADP (By similarity).`

Sequence information

Length: 599 AA [This is the length of the unprocessed precursor]

Molecular weight: 66252 Da [This is the MW of the unprocessed precursor]

CRC64: CA493E97DA034046 [This is a checksum on the sequence]

        10         20         30         40         50         60 
MTTQVPPSAL LPLNPEQLAR LQAATTDLTP TQLAWVSGYF WGVLNQQPAA LAATPAPAAE 

        70         80         90        100        110        120 
MPGITIISAS QTGNARRVAE ALRDDLLAAK LNVKLVNAGD YKFKQIASEK LLIVVTSTQG 

       130        140        150        160        170        180 
EGEPPEEAVA LHKFLFSKKA PKLENTAFAV FSLGDSSYEF FCQSGKDFDS KLAELGGERL 

       190        200        210        220        230        240 
LDRVDADVEY QAAASEWRAR VVDALKSRAP VAAPSQSVAT GAVNEIHTSP YSKDAPLVAS 

       250        260        270        280        290        300 
LSVNQKITGR NSEKDVRHIE IDLGDSGLRY QPGDALGVWY QNDPALVKEL VELLWLKGDE 

       310        320        330        340        350        360 
PVTVEGKTLP LNEALQWHFE LTVNTANIVE NYATLTRSET LLPLVGDKAK LQHYAATTPI 

       370        380        390        400        410        420 
VDMVRFSPAQ LDAEALINLL RPLTPRLYSI ASSQAEVENE VHVTVGVVRY DVEGRARAGG 

       430        440        450        460        470        480 
ASSFLADRVE EEGEVRVFIE HNDNFRLPAN PETPVIMIGP GTGIAPFRAF MQQRAADEAP 

       490        500        510        520        530        540 
GKNWLFFGNP HFTEDFLYQV EWQRYVKDGV LTRIDLAWSR DQKEKVYVQD KLREQGAELW 

       550        560        570        580        590 
RWINDGAHIY VCGDANRMAK DVEQALLEVI AEFGGMDTEA ADEFLSELRV ERRYQRDVY

B1IU77 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