O47499 (CYB_METSE) Reviewed, UniProtKB/Swiss-Prot

Names and origin

Protein names

Recommended name:
Cytochrome b

Alternative name(s):
Complex III subunit 3
Complex III subunit III
Cytochrome b-c1 complex subunit 3
Ubiquinol-cytochrome-c reductase complex cytochrome b subunit

Gene names

Name:	MT-CYB
Synonyms:	COB, CYTB, MTCYB

Encoded on

Mitochondrion

Organism

Metridium senile (Brown sea anemone) (Frilled sea anemone)

Taxonomic identifier

6116 [NCBI]

Taxonomic lineage

cellular organisms › Eukaryota › Opisthokonta › Metazoa › Eumetazoa › Cnidaria › Anthozoa › Hexacorallia › Actiniaria › Nynantheae › Metridiidae › Metridium

Protein attributes

Sequence length	393 AA.
Sequence status	Complete.
Protein existence	Inferred from homology

General annotation (Comments)

Function	Component of the ubiquinol-cytochrome c reductase complex (complex III or cytochrome b-c1 complex), which is a respiratory chain that generates an electrochemical potential coupled to ATP synthesis By similarity.
Cofactor	Binds 2 heme groups non-covalently By similarity.
Subunit structure	The main subunits of complex b-c1 are: cytochrome b, cytochrome c1 and the Rieske protein By similarity.
Subcellular location	Mitochondrion inner membrane; Multi-pass membrane protein By similarity.
Miscellaneous	Heme 1 (or BL or b562) is low-potential and absorbs at about 562 nm, and heme 2 (or BH or b566) is high-potential and absorbs at about 566 nm By similarity.
Sequence similarities	Belongs to the cytochrome b family.

Ontologies

Keywords
Biological process	Electron transport Respiratory chain Transport
Cellular component	Membrane Mitochondrion Mitochondrion inner membrane
Domain	Transmembrane Transmembrane helix
Ligand	Heme Iron Metal-binding
Gene Ontology (GO)
Biological_process	respiratory electron transport chain Inferred from electronic annotation. Source: InterPro
Cellular_component	integral to membrane Inferred from electronic annotation. Source: UniProtKB-KW mitochondrial inner membrane Inferred from electronic annotation. Source: UniProtKB-SubCell respiratory chain Inferred from electronic annotation. Source: UniProtKB-KW
Molecular_function	electron carrier activity Inferred from electronic annotation. Source: InterPro metal 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 – 393	393	Cytochrome b		PRO_0000061174
Regions
	Transmembrane	21 – 41	21	Helical; Potential
	Transmembrane	44 – 64	21	Helical; Potential
	Transmembrane	87 – 107	21	Helical; Potential
	Transmembrane	126 – 146	21	Helical; Potential
	Transmembrane	161 – 181	21	Helical; Potential
	Transmembrane	189 – 209	21	Helical; Potential
	Transmembrane	242 – 262	21	Helical; Potential
	Transmembrane	272 – 292	21	Helical; Potential
	Transmembrane	299 – 319	21	Helical; Potential
	Transmembrane	334 – 354	21	Helical; Potential
	Transmembrane	357 – 377	21	Helical; Potential
Sites
	Metal binding	94	1	Iron 1 (heme b562 axial ligand)
	Metal binding	108	1	Iron 2 (heme b566 axial ligand)
	Metal binding	193	1	Iron 1 (heme b562 axial ligand)
	Metal binding	207	1	Iron 2 (heme b566 axial ligand)

Sequences

	Sequence		Length	Mass (Da)
	O47499 [UniParc]. Last modified June 1, 1998. Version 1. Checksum: 751D80091F0BE073	FASTA	393	44,260
	10 20 30 40 50 60 MVGYAMGHSR PTMQFRKENP VLSIVNGIII DLPAPANLSY MWNFGSLLGV CLVVQMATGI 70 80 90 100 110 120 FLAMHYCSDV SLAFASVDHI MRDVNYGFLL RYFHANGASM FFLCLYFHVG RGIYYGSYTK 130 140 150 160 170 180 VEVWNVGVVL FILTMATAFL GYVLPWGQMS FWGATVITNL LSAIPYVGTD IVQWVWGGFS 190 200 210 220 230 240 VSNATLNRFF SLHYLLPFVL AALGVVHLIC LHVSGSNNPI GVRSDLDKVP FHTYYTSKDW 250 260 270 280 290 300 YGIVAFVLFF CSLVYLAPNL LGDPENFIQA NPLVTPVHIQ PEWYFLFAYA ILRSIPNKLG 310 320 330 340 350 360 GVVAMFASLL ILFLLPWVHT SRLRGLTFRP LARVAFWFMV TDFMLLTWIG CQPVEEPFII 370 380 390 VGQLASVFFF AYFLVLSPLL GYLENLLLFP KKG

References

[1]	"Mitochondrial DNA of the sea anemone, Metridium senile (Cnidaria): prokaryote-like genes for tRNA(f-Met) and small-subunit ribosomal RNA, and standard genetic code specificities for AGR and ATA codons." Pont-Kingdon G.A., Beagley C.T., Okimoto R., Wolstenholme D.R. J. Mol. Evol. 39:387-399(1994) [PubMed] [Europe PMC] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [GENOMIC DNA].
[2]	Beagley C.T., Okimoto R., Wolstenholme D.R. Submitted (APR-1997) to the EMBL/GenBank/DDBJ databases Cited for: NUCLEOTIDE SEQUENCE [GENOMIC DNA]. Strain: White morph.

Cross-references

Sequence databases
EMBL GenBank DDBJ	S75445 Genomic DNA. Translation: AAB32501.1. AF000023 Genomic DNA. Translation: AAC04642.1.
PIR	T11896.
RefSeq	NP_009265.2. NC_000933.1.
3D structure databases
ProteinModelPortal	O47499.
SMR	O47499. Positions 16-388.
ModBase	Search...
Protocols and materials databases
StructuralBiologyKnowledgebase	Search...
Genome annotation databases
GeneID	808781.
Organism-specific databases
CTD	4519.
Phylogenomic databases
ProtClustDB	MTH00022.
Family and domain databases
InterPro	IPR016175. Cyt_b/b6. IPR005798. Cyt_b/b6_C. IPR005797. Cyt_b/b6_N. IPR016174. Di-haem_cyt_TM. [Graphical view]
PANTHER	PTHR19271. PTHR19271. 1 hit.
Pfam	PF00032. Cytochrom_B_C. 1 hit. PF13631. Cytochrom_B_N_2. 1 hit. [Graphical view]
SUPFAM	SSF81648. Cytochrome_b/b6_C. 1 hit. SSF81342. Transmembr_di-haem_cytochrome. 1 hit.
PROSITE	PS51003. CYTB_CTER. 1 hit. PS51002. CYTB_NTER. 1 hit. [Graphical view]
ProtoNet	Search...

Entry information

Entry name

CYB_METSE

Accession

Primary (citable) accession number: O47499
Secondary accession number(s): Q26384

Entry history

Integrated into UniProtKB/Swiss-Prot:	December 15, 1998
Last sequence update:	June 1, 1998
Last modified:	May 1, 2013
This is version 66 of the entry and version 1 of the sequence. [Complete history]

Entry status

Reviewed (UniProtKB/Swiss-Prot)