Reviewed, UniProtKB/Swiss-Prot A5F3I5 (CYSI_VIBC3)

Names and origin

Protein names

Recommended name:
    Sulfite reductase [NADPH] hemoprotein beta-component
      Short name=SIR-HP
      Short name=SIRHP
    EC=1.8.1.2

Gene names

Name:	cysI
Ordered Locus Names:	VC0395_A2796

Organism

Vibrio cholerae serotype O1 (strain ATCC 39541 / Ogawa 395 / O395) [Complete proteome] [HAMAP]

Taxonomic identifier

345073 [NCBI]

Taxonomic lineage

Bacteria › Proteobacteria › Gammaproteobacteria › Vibrionales › Vibrionaceae › Vibrio

Protein attributes

Sequence length	577 AA.
Sequence status	Complete.
Sequence processing	The displayed sequence is not processed.
Protein existence	Inferred from homology.

General annotation (Comments)

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	H(2)S + 3 NADP(+) + 3 H(2)O = sulfite + 3 NADPH.
Cofactor	Binds 1 siroheme per subunit By similarity. Binds 1 4Fe-4S cluster per subunit By similarity.
Subunit structure	Alpha(8)-beta(4). The alpha component is a flavoprotein, the beta component is a hemoprotein By similarity.
Sequence similarities	Belongs to the nitrite and sulfite reductase 4Fe-4S domain family.

Ontologies

Keywords
Biological process	Amino-acid biosynthesis Cysteine biosynthesis
Ligand	4Fe-4S Heme Iron Iron-sulfur Metal-binding NADP
Molecular function	Oxidoreductase
Technical term	Complete proteome
Gene Ontology (GO)
Biological process	cysteine biosynthetic process Inferred from electronic annotation. Source: UniProtKB-KW oxidation reduction Inferred from electronic annotation. Source: UniProtKB-KW sulfate assimilation Inferred from electronic annotation. Source: HAMAP
Cellular component	sulfite reductase complex (NADPH) Inferred from electronic annotation. Source: InterPro
Molecular function	4 iron, 4 sulfur cluster binding Inferred from electronic annotation. Source: InterPro NADP binding Inferred from electronic annotation. Source: InterPro electron carrier activity Inferred from electronic annotation. Source: InterPro heme binding Inferred from electronic annotation. Source: InterPro iron ion binding Inferred from electronic annotation. Source: UniProtKB-KW sulfite reductase (NADPH) activity Inferred from electronic annotation. Source: HAMAP
Complete GO annotation...

Sequence annotation (Features)

	Feature key	Position(s)	Length	Description	Graphical view	Feature identifier
Molecule processing
	Chain	1 – 577	577	Sulfite reductase [NADPH] hemoprotein beta-component		PRO_1000073552
Sites
	Metal binding	440	1	Iron-sulfur (4Fe-4S) By similarity
	Metal binding	446	1	Iron-sulfur (4Fe-4S) By similarity
	Metal binding	486	1	Iron-sulfur (4Fe-4S) By similarity
	Metal binding	490	1	Iron (siroheme axial ligand) By similarity
	Metal binding	490	1	Iron-sulfur (4Fe-4S) By similarity

Sequences

	Sequence		Length	Mass (Da)
	A5F3I5-1 [UniParc]. Last modified June 12, 2007. Version 1. Checksum: 807070BF8B98E6DA	FASTA	577	64,371
	10 20 30 40 50 60 MSANQNPSVQ EVLGEVLGPW SDNERLKRES HFLRGTIEQD LQDRITGGFT ADNFQLIRFH 70 80 90 100 110 120 GMYQQDDRDI RAERSKQKLE PLHNVMLRAR MPGGIITPHQ WLAIDKFATE HTLYGSIRLT 130 140 150 160 170 180 TRQTFQFHGV LKPNIKLMHQ TLNSIGIDSI ATAGDVNRNV LCTSNPVESQ LHLQAYEWAK 190 200 210 220 230 240 KISEHLLPKT RAYAEIWLDG EKIEGPDEEP ILGSNYLPRK FKTTVVIPPH NDVDVHANDL 250 260 270 280 290 300 NFVAIGENGQ LIGFNVLVGG GLAMTHGDTS TYPRRADDFG FIPLEKTLEV AAAVVSTQRD 310 320 330 340 350 360 WGNRSNRKNA KTKYTLDRVG VEVFKAEVEK RAGITFAPSR AYEFTSRGDR IGWVEGIDGK 370 380 390 400 410 420 HHLTLFIENG RILDFPGKPL KTGVAEIAKV HQGDFRMTAN QNLIVAGVPA DQKQQIEQLA 430 440 450 460 470 480 RSHGLIDDGV SEQRINSMAC VAFPTCPLAM AEAERFLPSF VTEVEGILAK HALPKEENII 490 500 510 520 530 540 LRVTGCPNGC GRAMLAEIGL VGKAPGRYNL HLGGNRNGTR IPKMYKENIT DTQILQEIDE 550 560 570 LVGRWASERL DGEGFGDFTI RAGIIEEVII SKRDFYA

References

[1]	Heidelberg J. Submitted (MAR-2007) to the EMBL/GenBank/DDBJ databases Cited for: NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].

Cross-references

Sequence databases
EMBLGenBankDDBJ	CP000627 Genomic DNA. Translation: ABQ21061.1.
RefSeq	YP_001218654.1.
3D structure databases
ModBase	Search...
Genome annotation databases
GeneID	5135522.
GenomeReviews	Gene locus VC0395_A2796 in contig CP000627_GR.
KEGG	vco:VC0395_A2796.
Organism-specific databases
CMR	Search...
Family and domain databases
HAMAP	MF_01540. [Tree]
InterPro	IPR011786. CysI. IPR006066. Nir_Si_BS. IPR006067. Nir_Sir_4Fe4S. IPR005117. NiRdtase/SiRdtase_haem-b_fer. [Graphical view]
Pfam	PF01077. NIR_SIR. 1 hit. PF03460. NIR_SIR_ferr. 2 hits. [Graphical view]
PRINTS	PR00397. SIROHAEM.
TIGRFAMs	TIGR02041. CysI. 1 hit.
PROSITE	PS00365. NIR_SIR. 1 hit. [Graphical view]
ProtoNet	Search...

Entry information

Entry name

CYSI_VIBC3

Accession

Primary (citable) accession number: A5F3I5

Entry history

Integrated into UniProtKB/Swiss-Prot:	February 26, 2008
Last sequence update:	June 12, 2007
Last modified:	November 25, 2008
This is version 13 of the entry and version 1 of the sequence. [Complete history]

Entry status

Reviewed (UniProtKB/Swiss-Prot)

Annotation project

HAMAP (High-quality Automated and Manual Annotation of microbial Proteomes)