Q36192 · CYB_URSAR
- ProteinCytochrome b
- GeneMT-CYB
- StatusUniProtKB reviewed (Swiss-Prot)
- Amino acids379 (go to sequence)
- Protein existenceInferred from homology
- Annotation score5/5
Function
function
Component of the ubiquinol-cytochrome c reductase complex (complex III or cytochrome b-c1 complex) that is part of the mitochondrial respiratory chain. The b-c1 complex mediates electron transfer from ubiquinol to cytochrome c. Contributes to the generation of a proton gradient across the mitochondrial membrane that is then used for ATP synthesis.
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.
Cofactor
Note: Binds 2 heme b groups non-covalently.
Features
Showing features for binding site.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Binding site | 83 | Fe (UniProtKB | ChEBI) of heme b b562 (UniProtKB | ChEBI); axial binding residue | ||||
Sequence: H | ||||||
Binding site | 97 | Fe (UniProtKB | ChEBI) of heme b b566 (UniProtKB | ChEBI); axial binding residue | ||||
Sequence: H | ||||||
Binding site | 182 | Fe (UniProtKB | ChEBI) of heme b b562 (UniProtKB | ChEBI); axial binding residue | ||||
Sequence: H | ||||||
Binding site | 196 | Fe (UniProtKB | ChEBI) of heme b b566 (UniProtKB | ChEBI); axial binding residue | ||||
Sequence: H | ||||||
Binding site | 201 | a ubiquinone (UniProtKB | ChEBI) | ||||
Sequence: H |
GO annotations
Aspect | Term | |
---|---|---|
Cellular Component | mitochondrial inner membrane | |
Cellular Component | respiratory chain complex III | |
Molecular Function | metal ion binding | |
Molecular Function | ubiquinol-cytochrome-c reductase activity | |
Biological Process | respiratory electron transport chain |
Keywords
- Biological process
- Ligand
Names & Taxonomy
Protein names
- Recommended nameCytochrome b
- Alternative names
Gene names
Encoded on
- Mitochondrion
Organism names
- Taxonomic lineageEukaryota > Metazoa > Chordata > Craniata > Vertebrata > Euteleostomi > Mammalia > Eutheria > Laurasiatheria > Carnivora > Caniformia > Ursidae > Ursus
Accessions
- Primary accessionQ36192
- Secondary accessions
Subcellular Location
UniProt Annotation
GO Annotation
Mitochondrion inner membrane ; Multi-pass membrane protein
Features
Showing features for transmembrane.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Transmembrane | 33-53 | Helical | ||||
Sequence: FGSLLGVCLILQILTGLFLAM | ||||||
Transmembrane | 77-98 | Helical | ||||
Sequence: WVIRYVHANGASIFFICLFMHV | ||||||
Transmembrane | 113-133 | Helical | ||||
Sequence: WNIGIILLFTIMATAFMGYVL | ||||||
Transmembrane | 178-198 | Helical | ||||
Sequence: FFAFHFILPFIILALAAVHLL | ||||||
Transmembrane | 226-246 | Helical | ||||
Sequence: IKDILGALLLALTLATLVLFS | ||||||
Transmembrane | 288-308 | Helical | ||||
Sequence: LGGVLALIFSILILAIIPLLH | ||||||
Transmembrane | 320-340 | Helical | ||||
Sequence: LSQCLFWLLVADLLTLTWIGG | ||||||
Transmembrane | 347-367 | Helical | ||||
Sequence: FIIIGQLASILYFTILLVLMP |
Keywords
- Cellular component
Phenotypes & Variants
Features
Showing features for natural variant.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Natural variant | 57 | in lineages GB01, GB02, GB03, GB04 and GB05 | ||||
Sequence: P → S | ||||||
Natural variant | 89 | in lineages GB01, GB02, GB03, GB04 and GB05 | ||||
Sequence: I → M | ||||||
Natural variant | 110 | in lineages GB01, GB02, GB03, GB04, GB05, GB08, GB09, GB10, GB12, GB14 and GB17 | ||||
Sequence: P → S | ||||||
Natural variant | 123 | in lineages GB01, GB02, GB03, GB04 and GB05 | ||||
Sequence: I → V | ||||||
Natural variant | 153 | in lineages GB01, GB02, GB03 and GB05 | ||||
Sequence: I → V | ||||||
Natural variant | 236 | in lineages GB01, GB02, GB03, GB04 and GB05 | ||||
Sequence: A → T | ||||||
Natural variant | 238 | in lineages GB01, GB02, GB03, GB04 and GB05 | ||||
Sequence: T → A | ||||||
Natural variant | 257 | in lineages GB01, GB02, GB03, GB04 and GB05 | ||||
Sequence: T → I | ||||||
Natural variant | 303 | in lineages GB01, GB02, GB03, GB04 and GB05 | ||||
Sequence: I → L | ||||||
Natural variant | 368 | in lineage GB01 | ||||
Sequence: I → T | ||||||
Natural variant | 375 | in lineages GB10 and GB12 | ||||
Sequence: N → S |
Variants
We now provide the "Disease & Variants" viewer in its own tab.
The viewer provides 11 variants from UniProt as well as other sources including ClinVar and dbSNP.
PTM/Processing
Features
Showing features for chain.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Chain | PRO_0000061703 | 1-379 | Cytochrome b | |||
Sequence: MTNIRKTHPLAKIINNSFIDLPTPSNISAWWNFGSLLGVCLILQILTGLFLAMHYTPDTTTAFSSVTHICRDVHYGWVIRYVHANGASIFFICLFMHVGRGLYYGSYLFPETWNIGIILLFTIMATAFMGYVLPWGQMSFWGATVITNLLSAIPYIGTDLVEWIWGGFSVDKATLTRFFAFHFILPFIILALAAVHLLFLHETGSNNPSGIPSDSDKIPFHPYYTIKDILGALLLALTLATLVLFSPDLLGDPDNYTPANPLSTPPHIKPEWYFLFAYAILRSIPNKLGGVLALIFSILILAIIPLLHTSKQRGMMFRPLSQCLFWLLVADLLTLTWIGGQPVEHPFIIIGQLASILYFTILLVLMPIAGIIENNLLKW |
Interaction
Subunit
The cytochrome bc1 complex contains 11 subunits: 3 respiratory subunits (MT-CYB, CYC1 and UQCRFS1), 2 core proteins (UQCRC1 and UQCRC2) and 6 low-molecular weight proteins (UQCRH/QCR6, UQCRB/QCR7, UQCRQ/QCR8, UQCR10/QCR9, UQCR11/QCR10 and a cleavage product of UQCRFS1). This cytochrome bc1 complex then forms a dimer.
Structure
Sequence
- Sequence statusComplete
- Length379
- Mass (Da)42,459
- Last updated1997-11-01 v1
- Checksum0D82449AD05FF329
Polymorphism
Sequenced in lineages GB01 to GB26.
Sequence databases
Nucleotide Sequence | Protein Sequence | Molecule Type | Status | |
---|---|---|---|---|
U18870 EMBL· GenBank· DDBJ | AAB38167.1 EMBL· GenBank· DDBJ | Genomic DNA | ||
U18871 EMBL· GenBank· DDBJ | AAB38168.1 EMBL· GenBank· DDBJ | Genomic DNA | ||
U18872 EMBL· GenBank· DDBJ | AAB38169.1 EMBL· GenBank· DDBJ | Genomic DNA | ||
U18873 EMBL· GenBank· DDBJ | AAB38170.1 EMBL· GenBank· DDBJ | Genomic DNA | ||
U18874 EMBL· GenBank· DDBJ | AAB38171.1 EMBL· GenBank· DDBJ | Genomic DNA | ||
U18875 EMBL· GenBank· DDBJ | AAB38172.1 EMBL· GenBank· DDBJ | Genomic DNA | ||
U18876 EMBL· GenBank· DDBJ | AAB38173.1 EMBL· GenBank· DDBJ | Genomic DNA | ||
U18877 EMBL· GenBank· DDBJ | AAB38174.1 EMBL· GenBank· DDBJ | Genomic DNA | ||
U18878 EMBL· GenBank· DDBJ | AAB38175.1 EMBL· GenBank· DDBJ | Genomic DNA | ||
U18879 EMBL· GenBank· DDBJ | AAB38176.1 EMBL· GenBank· DDBJ | Genomic DNA | ||
U18880 EMBL· GenBank· DDBJ | AAB38177.1 EMBL· GenBank· DDBJ | Genomic DNA | ||
U18881 EMBL· GenBank· DDBJ | AAB38178.1 EMBL· GenBank· DDBJ | Genomic DNA | ||
U18882 EMBL· GenBank· DDBJ | AAB38179.1 EMBL· GenBank· DDBJ | Genomic DNA | ||
U18883 EMBL· GenBank· DDBJ | AAB38180.1 EMBL· GenBank· DDBJ | Genomic DNA | ||
U18884 EMBL· GenBank· DDBJ | AAB38181.1 EMBL· GenBank· DDBJ | Genomic DNA | ||
U18885 EMBL· GenBank· DDBJ | AAB38182.1 EMBL· GenBank· DDBJ | Genomic DNA | ||
U18886 EMBL· GenBank· DDBJ | AAB38183.1 EMBL· GenBank· DDBJ | Genomic DNA | ||
U18887 EMBL· GenBank· DDBJ | AAB38184.1 EMBL· GenBank· DDBJ | Genomic DNA | ||
U18888 EMBL· GenBank· DDBJ | AAB38185.1 EMBL· GenBank· DDBJ | Genomic DNA | ||
U18889 EMBL· GenBank· DDBJ | AAB38186.1 EMBL· GenBank· DDBJ | Genomic DNA | ||
U18890 EMBL· GenBank· DDBJ | AAB38187.1 EMBL· GenBank· DDBJ | Genomic DNA | ||
U18891 EMBL· GenBank· DDBJ | AAB38188.1 EMBL· GenBank· DDBJ | Genomic DNA | ||
U18892 EMBL· GenBank· DDBJ | AAB38189.1 EMBL· GenBank· DDBJ | Genomic DNA | ||
U18893 EMBL· GenBank· DDBJ | AAB38190.1 EMBL· GenBank· DDBJ | Genomic DNA | ||
U18894 EMBL· GenBank· DDBJ | AAB38191.1 EMBL· GenBank· DDBJ | Genomic DNA | ||
U18895 EMBL· GenBank· DDBJ | AAB38192.1 EMBL· GenBank· DDBJ | Genomic DNA | ||
U18896 EMBL· GenBank· DDBJ | AAB38193.1 EMBL· GenBank· DDBJ | Genomic DNA | ||
U18897 EMBL· GenBank· DDBJ | AAB38194.1 EMBL· GenBank· DDBJ | Genomic DNA | ||
X82308 EMBL· GenBank· DDBJ | CAA57751.1 EMBL· GenBank· DDBJ | Genomic DNA | ||
U12855 EMBL· GenBank· DDBJ | AAA67259.1 EMBL· GenBank· DDBJ | Genomic DNA |