Q7NJB3 (CYB6_GLOVI) Reviewed, UniProtKB/Swiss-Prot

Names and origin

Protein names

Recommended name:
Cytochrome b6

Gene names

Name:	petB
Ordered Locus Names:	gll1919

Organism

Gloeobacter violaceus (strain PCC 7421)

Taxonomic identifier

251221 [NCBI]

Taxonomic lineage

Bacteria › Cyanobacteria › Gloeobacteria › Gloeobacterales › Gloeobacter

Protein attributes

Sequence length	215 AA.
Sequence status	Complete.
Protein existence	Inferred from homology

General annotation (Comments)

Function	Component of the cytochrome b6-f complex, which mediates electron transfer between photosystem II (PSII) and photosystem I (PSI), cyclic electron flow around PSI, and state transitions 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 4 large subunits of the cytochrome b6-f complex are cytochrome b6, subunit IV (17 kDa polypeptide, PetD), cytochrome f and the Rieske protein, while the 4 small subunits are PetG, PetL, PetM and PetN. The complex functions as a dimer By similarity.
Subcellular location	Cell inner 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 inner membrane Cell membrane Membrane
Domain	Transmembrane Transmembrane helix
Ligand	Heme Iron Metal-binding
Technical term	Complete proteome Reference proteome
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 – 215	215	Cytochrome b6 HAMAP MF_00633		PRO_0000061826
Regions
	Transmembrane	32 – 52	21	Helical; Potential
	Transmembrane	90 – 110	21	Helical; Potential
	Transmembrane	116 – 136	21	Helical; Potential
	Transmembrane	186 – 206	21	Helical; Potential
Sites
	Metal binding	86	1	Iron (heme 2 axial ligand) By similarity
	Metal binding	100	1	Iron (heme 1 axial ligand) By similarity
	Metal binding	187	1	Iron (heme 2 axial ligand) By similarity
	Metal binding	202	1	Iron (heme 1 axial ligand) By similarity
	Binding site	35	1	Heme 1 (covalent; via 1 link) By similarity

Sequences

	Sequence		Length	Mass (Da)
	Q7NJB3 [UniParc]. Last modified December 15, 2003. Version 1. Checksum: 43235E2C3660CE13	FASTA	215	24,337
	10 20 30 40 50 60 MSKVYDWFQE RLEVQALADD ITSKYVPPHV NIFYCLGGVT LICFLVQFAT GFAMTYYYKP 70 80 90 100 110 120 TVAEAFSSVN YIMDEVSFGW LIRSIHRWSA SMMVLAMILH TFRVYLTGGF KRPRELTWVT 130 140 150 160 170 180 GVLLACLTVS FGVTGYSLPW DQVGYWAVKI VTQVPSAIPV VGDLIVEFLR GGAGVGQETL 190 200 210 TRFYSAHTFV LPWLTVVFML MHFLMIRKQG ISGPL

References

[1]

"Complete genome structure of Gloeobacter violaceus PCC 7421, a cyanobacterium that lacks thylakoids." Nakamura Y., Kaneko T., Sato S., Mimuro M., Miyashita H., Tsuchiya T., Sasamoto S., Watanabe A., Kawashima K., Kishida Y., Kiyokawa C., Kohara M., Matsumoto M., Matsuno A., Nakazaki N., Shimpo S., Takeuchi C., Yamada M., Tabata S. DNA Res. 10:137-145(2003) [PubMed: 14621292] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA]. Strain: PCC 7421.

Cross-references

Sequence databases
EMBL GenBank DDBJ	BA000045 Genomic DNA. Translation: BAC89860.1.
RefSeq	NP_924865.1. NC_005125.1.
3D structure databases
ProteinModelPortal	Q7NJB3.
SMR	Q7NJB3. Positions 1-215.
ModBase	Search...
Protocols and materials databases
StructuralBiologyKnowledgebase	Search...
Genome annotation databases
GeneID	2600321.
GenomeReviews	Gene locus gll1919 in contig BA000045_GR.
NMPDR	fig|251221.1.peg.1919.
PATRIC	22043295. VBIGloVio86258_1953.
Phylogenomic databases
HOGENOM	HBG286086.
OMA	ATLTRFY.
ProtClustDB	PRK03735.
Enzyme and pathway databases
BioCyc	GVIO251221:GLL1919-MONOMER.
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_GLOVI

Accession

Primary (citable) accession number: Q7NJB3

Entry history

Integrated into UniProtKB/Swiss-Prot:	July 19, 2004
Last sequence update:	December 15, 2003
Last modified:	January 25, 2012
This is version 60 of the entry and version 1 of the sequence. [Complete history]

Entry status

Reviewed (UniProtKB/Swiss-Prot)

Annotation program

Prokaryotic Protein Annotation Program