Reviewed, UniProtKB/Swiss-Prot Q493N3 (CYSI_BLOPB)

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:	BPEN_164

Organism

Blochmannia pennsylvanicus (strain BPEN) [Complete proteome] [HAMAP]

Taxonomic identifier

291272 [NCBI]

Taxonomic lineage

Bacteria › Proteobacteria › Gammaproteobacteria › Enterobacteriales › Enterobacteriaceae › ant endosymbionts › Candidatus Blochmannia

Protein attributes

Sequence length	575 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. HAMAP MF_01540
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 – 575	575	Sulfite reductase [NADPH] hemoprotein beta-component HAMAP MF_01540		PRO_0000292959
Sites
	Metal binding	439	1	Iron-sulfur (4Fe-4S) By similarity
	Metal binding	445	1	Iron-sulfur (4Fe-4S) By similarity
	Metal binding	484	1	Iron-sulfur (4Fe-4S) By similarity
	Metal binding	488	1	Iron (siroheme axial ligand) By similarity
	Metal binding	488	1	Iron-sulfur (4Fe-4S) By similarity

Sequences

	Sequence		Length	Mass (Da)
	Q493N3-1 [UniParc]. Last modified September 13, 2005. Version 1. Checksum: CAF03E18C47DDE31	FASTA	575	65,260
	10 20 30 40 50 60 MNRKYDNNND KNIPLLSDNE RIKKESNFLR GTIAQNLDNN LTGGFNTEDA QLIRFHGMYQ 70 80 90 100 110 120 QDDRDVRVER ANQKLEPLIN MMLRCRLPGG VIMPQQWLAI DDFSEKYTLY GTIRLTTRQT 130 140 150 160 170 180 FQLHGLLKPN LKNVHRLLNK LGLDSIATAG DVNRNVICTA NPMESTLHYQ VWELAKSISS 190 200 210 220 230 240 YLLPKSNAYA EIWLDSKKTE STDSEPILSA TYLPRKFKIA IAIPPINDVD VHANDLSFIA 250 260 270 280 290 300 IKSENTDQII GFNVLVGGGL AMTYGDITTY PRKASAFGYI STKDVLKIAE TVVTVQRDWG 310 320 330 340 350 360 NRSDRRHAKT KYTLTRVGVT TFKSEVERRS GVQFHPIRPY VFTDRGDRFG WVQGIDDYWH 370 380 390 400 410 420 LTLFIENGRI SNNDPHKLLK RGIAEVAQIH SGSFRLTANQ NLIISGVSKD NKLMIESTLR 430 440 450 460 470 480 KYGVINDDIT PQRKASMACV AFPTCPLAMA EAERFLPKFV TKIEHIMSKY RLEKDAIILR 490 500 510 520 530 540 VTGCPNSCAR AMLSEIGLTG RSIGRYNLYL GGNNIGTRIP RLYKENITEN DILNILDTTI 550 560 570 SRWAQERNSQ ESYGDYVVRS GIVNAVINSE KDFYE

References

[1]	"Genome sequence of Blochmannia pennsylvanicus indicates parallel evolutionary trends among bacterial mutualists of insects." Degnan P.H., Lazarus A.B., Wernegreen J.J. Genome Res. 15:1023-1033(2005) [PubMed: 16077009] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].

Cross-references

Sequence databases
EMBLGenBankDDBJ	CP000016 Genomic DNA. Translation: AAZ40804.1.
RefSeq	YP_277677.1.
3D structure databases
ModBase	Search...
Genome annotation databases
GeneID	3563110.
GenomeReviews	Gene locus BPEN_164 in contig CP000016_GR.
KEGG	bpn:BPEN_164.
Organism-specific databases
CMR	Search...
Phylogenomic databases
HOGENOM	Q493N3.
Enzyme and pathway databases
BioCyc	CBLO291272:BPEN_164-MON.
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_BLOPB

Accession

Primary (citable) accession number: Q493N3

Entry history

Integrated into UniProtKB/Swiss-Prot:	June 26, 2007
Last sequence update:	September 13, 2005
Last modified:	November 25, 2008
This is version 21 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)