Q9L598 (CYB6_HELGE) Reviewed, UniProtKB/Swiss-Prot

Names and origin

Protein names

Recommended name:
Cytochrome b6

Gene names

Name:	petB
Synonyms:	cytB

Organism

Heliobacterium gestii

Taxonomic identifier

2699 [NCBI]

Taxonomic lineage

Bacteria › Firmicutes › Clostridia › Clostridiales › Heliobacteriaceae › Heliobacterium

Protein attributes

Sequence length	213 AA.
Sequence status	Complete.
Protein existence	Inferred from homology

General annotation (Comments)

Function	Component of the cytochrome bc complex which donates electrons to the photosynthetic reaction center By similarity. HAMAP MF_00633
Cofactor	Binds 2 heme groups. One heme group is bound covalently by a single cysteine link, the other one non-covalently By similarity.
Subunit structure	The subunits of the cytochrome bc complex are a Rieske Fe-S protein (PetC), cytochrome b6 (PetB), subunit IV (PetD), and a diheme cytochrome c (PetX) By similarity.
Subcellular location	Cell membrane; Multi-pass membrane protein By similarity HAMAP MF_00633.
Miscellaneous	Heme 1 (or BH or b566) is high-potential and absorbs at about 566 nm, and heme 2 (or BL or b562) is low-potential and absorbs at about 562 nm By similarity. HAMAP MF_00633
Sequence similarities	Belongs to the cytochrome b family. PetB subfamily.

Ontologies

Keywords
Biological process	Electron transport Photosynthesis Transport
Cellular component	Cell membrane Membrane
Domain	Transmembrane Transmembrane helix
Ligand	Heme Iron Metal-binding
Gene Ontology (GO)
Biological process	photosynthesis Inferred from electronic annotation. Source: UniProtKB-KW respiratory electron transport chain Inferred from electronic annotation. Source: InterPro transport 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
Molecular function	electron transporter, transferring electrons within cytochrome b6/f complex of photosystem II activity Inferred from electronic annotation. Source: InterPro heme binding Inferred from electronic annotation. Source: InterPro oxidoreductase 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
	Chain	1 – 213	213	Cytochrome b6 HAMAP MF_00633		PRO_0000061839
Regions
	Transmembrane	30 – 50	21	Helical; Potential
	Transmembrane	88 – 108	21	Helical; Potential
	Transmembrane	114 – 134	21	Helical; Potential
	Transmembrane	184 – 204	21	Helical; Potential
Sites
	Metal binding	84	1	Iron (heme 2 axial ligand) By similarity
	Metal binding	98	1	Iron (heme 1 axial ligand) By similarity
	Metal binding	185	1	Iron (heme 2 axial ligand) By similarity
	Metal binding	200	1	Iron (heme 1 axial ligand) By similarity
	Binding site	33	1	Heme 1 (covalent; via 1 link) By similarity

Sequences

	Sequence		Length	Mass (Da)
	Q9L598 [UniParc]. Last modified October 1, 2000. Version 1. Checksum: 39B92AE67D133DD3	FASTA	213	24,004
	10 20 30 40 50 60 MKWLEERFPG IGHVAKDVAD HPVPSHTLNI FFCLGGLTLL CFIVQCLTGI FLAFYYKPTP 70 80 90 100 110 120 EAAFTSVQMI TNEVRFGSVI RSMHHWSCQL MILLVFLHML RVYYTGAFKR PRELNWVAGC 130 140 150 160 170 180 FLLVLSLALA FTGYLLPYEQ LSYWASVIGA ETANTLPVVG PTLKIMMQGG IKVTAEMLSR 190 200 210 FYVLHVMILP AVAIIFLVAH FIMIRVQGIS DPM

References

[1]	"Gene cluster coding for redox proteins of a putative cytochrome bc complex in Heliobacterium gestii." Albert I. Submitted (APR-2000) to the EMBL/GenBank/DDBJ databases Cited for: NUCLEOTIDE SEQUENCE [GENOMIC DNA]. Strain: Chainat.
+	Additional computationally mapped references.

Cross-references

Sequence databases
EMBL GenBank DDBJ	AF254191 Genomic DNA. Translation: AAF68086.1.
3D structure databases
ProteinModelPortal	Q9L598.
ModBase	Search...
Protocols and materials databases
StructuralBiologyKnowledgebase	Search...
Family and domain databases
HAMAP	MF_00633. Cytb6_f_cytb6. [Tree]
InterPro	IPR016175. Cyt_b/b6. IPR005797. Cyt_b/b6_N. IPR023530. Cyt_B6_PetB. IPR016174. Di-haem_cyt_TM. [Graphical view]
Gene3D	G3DSA:1.20.810.10. Cytochrome_b/b6. 1 hit.
PANTHER	PTHR19271. Cytochrome_b/b6. 1 hit.
Pfam	PF00033. Cytochrom_B_N. 1 hit. [Graphical view]
PIRSF	PIRSF000032. Cytochrome_b6. 1 hit.
SUPFAM	SSF81342. Transmembr_di-haem_cytochrome. 1 hit.
PROSITE	PS51002. CYTB_NTER. 1 hit. [Graphical view]
ProtoNet	Search...

Entry information

Entry name

CYB6_HELGE

Accession

Primary (citable) accession number: Q9L598

Entry history

Integrated into UniProtKB/Swiss-Prot:	April 11, 2003
Last sequence update:	October 1, 2000
Last modified:	September 21, 2011
This is version 63 of the entry and version 1 of the sequence. [Complete history]

Entry status

Reviewed (UniProtKB/Swiss-Prot)

Annotation program

Prokaryotic Protein Annotation Program