Reviewed, UniProtKB/Swiss-Prot Q9ZGG0 (CYB6_HELMO)

Names and origin

Protein names

Recommended name:
    Cytochrome b6

Gene names

Name:	petB
Synonyms:	cytB

Organism

Heliobacillus mobilis

Taxonomic identifier

28064 [NCBI]

Taxonomic lineage

Bacteria › Firmicutes › Clostridia › Clostridiales › Heliobacteriaceae › Heliobacillus

Protein attributes

Sequence length	213 AA.
Sequence status	Complete.
Sequence processing	The displayed sequence is not processed.
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.
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.
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.
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
Ligand	Heme Iron Metal-binding
Gene Ontology (GO)
Biological process	photosynthesis Inferred from electronic annotation. Source: HAMAP 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: HAMAP iron ion binding Inferred from electronic annotation. Source: UniProtKB-KW 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_0000061840
Regions
	Transmembrane	30 – 50	21	Potential
	Transmembrane	88 – 108	21	Potential
	Transmembrane	114 – 134	21	Potential
	Transmembrane	184 – 204	21	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)
	Q9ZGG0-1 [UniParc]. Last modified May 1, 1999. Version 1. Checksum: 99ABE0FF48CE8804	FASTA	213	23,712
	10 20 30 40 50 60 MNWLEERLPG IGKVAEDIAE HPVPSHTLNI FYCLGGLTLL AFLVQCVTGL FLALYYKPTP 70 80 90 100 110 120 EAAFASVQMI TNEVRFGATI RSLHHWAANL MILLVFLHML RVYYTGSFKK PRELNWLAGC 130 140 150 160 170 180 FLLVLSLGLA FTGYLLPYEQ LSYWASVIGA ETAGSLPVVG ATMKIMMQGG IKVTAEMLSR 190 200 210 FYVLHVMILP LVTIGFLVAH FIMIRVQGIS DPM

References

[1]	"Tracking molecular evolution of photosynthesis by characterization of a major photosynthesis gene cluster from Heliobacillus mobilis." Xiong J., Inoue K., Bauer C.E. Proc. Natl. Acad. Sci. U.S.A. 95:14851-14856(1998) [PubMed: 9843979] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [GENOMIC DNA].

Cross-references

Sequence databases
EMBLGenBankDDBJ	AF080002 Genomic DNA. Translation: AAC84019.1.
PIR	T31447.
3D structure databases
ModBase	Search...
Family and domain databases
HAMAP	MF_00633. [Tree]
InterPro	IPR016175. Cyt_b/b6. IPR005797. Cyt_b/b6_N. [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]
PROSITE	PS51002. CYTB_NTER. 1 hit. [Graphical view]
ProtoNet	Search...

Entry information

Entry name

CYB6_HELMO

Accession

Primary (citable) accession number: Q9ZGG0

Entry history

Integrated into UniProtKB/Swiss-Prot:	April 11, 2003
Last sequence update:	May 1, 1999
Last modified:	June 16, 2009
This is version 54 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)