Q46136 (UCRI_CHLLT) Reviewed, UniProtKB/Swiss-Prot

Names and origin

Protein names

Recommended name:
Cytochrome b6-f complex iron-sulfur subunit
EC=1.10.9.1

Alternative name(s):
Plastohydroquinone:plastocyanin oxidoreductase iron-sulfur protein
Rieske iron-sulfur protein
Short name=ISP
Short name=RISP

Gene names

Name:

petC

Organism

Chlorobium limicola f.sp. thiosulfatophilum

Taxonomic identifier

115852 [NCBI]

Taxonomic lineage

cellular organisms › Bacteria › Bacteroidetes/Chlorobi group › Chlorobi › Chlorobia › Chlorobiales › Chlorobiaceae › Chlorobaculum

Protein attributes

Sequence length	181 AA.
Sequence status	Complete.
Sequence processing	The displayed sequence is further processed into a mature form.
Protein existence	Evidence at protein level

General annotation (Comments)

Function	Component of the green S-bacteria bc-complex which consists of the Rieske protein and cytochrome b subunit and which appears to lack a cytochrome c1-equivalent. This complex has a comparatively low redox potential.
Catalytic activity	Plastoquinol + 2 oxidized plastocyanin + 2 H+(Side 1) = plastoquinone + 2 reduced plastocyanin + 2 H+(Side 2).
Cofactor	Binds 1 2Fe-2S cluster per subunit By similarity.
Subcellular location	Cell membrane; Multi-pass membrane protein Potential.
Miscellaneous	The Rieske protein is a high potential 2Fe-2S protein.
Sequence similarities	Contains 1 Rieske domain.

Ontologies

Keywords
Biological process	Electron transport Transport
Cellular component	Cell membrane Membrane
Domain	Transmembrane Transmembrane helix
Ligand	2Fe-2S Iron Iron-sulfur Metal-binding
Molecular function	Oxidoreductase
PTM	Disulfide bond
Technical term	Direct protein sequencing
Gene Ontology (GO)
Biological_process	electron transport chain Inferred from electronic annotation. Source: UniProtKB-KW
Cellular_component	integral to membrane Inferred from electronic annotation. Source: UniProtKB-KW plasma membrane Inferred from electronic annotation. Source: UniProtKB-SubCell thylakoid membrane Inferred from electronic annotation. Source: InterPro
Molecular_function	2 iron, 2 sulfur cluster binding Inferred from electronic annotation. Source: UniProtKB-KW metal ion binding Inferred from electronic annotation. Source: UniProtKB-KW plastoquinol--plastocyanin reductase activity Inferred from electronic annotation. Source: EC ubiquinol-cytochrome-c reductase activity Inferred from electronic annotation. Source: InterPro
Complete GO annotation...

Sequence annotation (Features)

	Feature key	Position(s)	Length	Description	Graphical view	Feature identifier
Molecule processing
	Initiator methionine	1	1	Removed Ref.1
	Chain	2 – 181	180	Cytochrome b6-f complex iron-sulfur subunit		PRO_0000127772
Regions
	Transmembrane	53 – 73	21	Helical; Potential
	Transmembrane	114 – 134	21	Helical; Potential
	Domain	85 – 178	94	Rieske
Sites
	Metal binding	124	1	Iron-sulfur (2Fe-2S) By similarity
	Metal binding	126	1	Iron-sulfur (2Fe-2S); via pros nitrogen By similarity
	Metal binding	142	1	Iron-sulfur (2Fe-2S) By similarity
	Metal binding	145	1	Iron-sulfur (2Fe-2S); via pros nitrogen By similarity
Amino acid modifications
	Disulfide bond	129 ↔ 144		By similarity

Sequences

	Sequence		Length	Mass (Da)
	Q46136 [UniParc]. Last modified January 23, 2007. Version 2. Checksum: BD897E2DD1B8D3C6	FASTA	181	19,039
	10 20 30 40 50 60 MAQTGNFKSP ARMSSLGQGA APASSGAVTG GKPREGGLKG VDFERRGFLH KIVGGVGAVV 70 80 90 100 110 120 AVSTLYPVVK YIIPPARKIK NVDELTVGKA SEVPDGKSKI FQFNEDKVIV VNKGGALTAV 130 140 150 160 170 180 SAVCTHLGCL VNWVDADNQY FCPCHGAKYK LTGEIISGPQ PLPLKQYKAR IEGDSIIISK A

References

[1]	"A transcription unit for the Rieske FeS-protein and cytochrome b in Chlorobium limicola." Schuetz M., Zirngibl S., le Coutre J., Buettner M., Xie D.-L., Nelson N., Deutzmann R., Hauska G. Photosyn. Res. 39:163-174(1994) Cited for: NUCLEOTIDE SEQUENCE [GENOMIC DNA], PROTEIN SEQUENCE OF 2-35.

Cross-references

Sequence databases
EMBL GenBank DDBJ	X73628 Genomic DNA. Translation: CAA52007.1.
PIR	S38460.
3D structure databases
ProteinModelPortal	Q46136.
ModBase	Search...
Protocols and materials databases
StructuralBiologyKnowledgebase	Search...
Family and domain databases
Gene3D	2.102.10.10. 1 hit.
InterPro	IPR014909. Cyt_b6-f_cplx_Fe-S_su. IPR017941. Rieske_2Fe-2S. IPR014349. Rieske_Fe-S_prot. IPR005805. Rieske_Fe-S_prot_C. [Graphical view]
PANTHER	PTHR10134. PTHR10134. 1 hit.
Pfam	PF08802. CytB6-F_Fe-S. 1 hit. PF00355. Rieske. 1 hit. [Graphical view]
PRINTS	PR00162. RIESKE.
SUPFAM	SSF50022. Rieske_dom. 1 hit.
PROSITE	PS51296. RIESKE. 1 hit. [Graphical view]
ProtoNet	Search...

Entry information

Entry name

UCRI_CHLLT

Accession

Primary (citable) accession number: Q46136

Entry history

Integrated into UniProtKB/Swiss-Prot:	November 1, 1997
Last sequence update:	January 23, 2007
Last modified:	March 6, 2013
This is version 76 of the entry and version 2 of the sequence. [Complete history]

Entry status

Reviewed (UniProtKB/Swiss-Prot)

Annotation program

Prokaryotic Protein Annotation Program