Q9XP81 · CYB_SMIHI
- ProteinCytochrome b
- GeneMT-CYB
- StatusUniProtKB reviewed (Swiss-Prot)
- Amino acids381 (go to sequence)
- Protein existenceInferred from homology
- Annotation score3/5
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 |
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 | mitochondrial electron transport, ubiquinol to cytochrome c |
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 > Metatheria > Dasyuromorphia > Dasyuridae > Sminthopsis
Accessions
- Primary accessionQ9XP81
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: FGSSLGVCLMIQISTGLFLAM | ||||||
Transmembrane | 77-98 | Helical | ||||
Sequence: WIIRNLHANGASMFFMCLFLHI | ||||||
Transmembrane | 113-133 | Helical | ||||
Sequence: WNIGVILLLTVMATAFVGYVL | ||||||
Transmembrane | 178-198 | Helical | ||||
Sequence: FFAFHFILPFIIMALVIVHLL | ||||||
Transmembrane | 226-246 | Helical | ||||
Sequence: IKDALGLMFLLLVLLSLALFS | ||||||
Transmembrane | 288-308 | Helical | ||||
Sequence: LGGVLALLASILILLVIPFLH | ||||||
Transmembrane | 320-340 | Helical | ||||
Sequence: ISQTLFWILTANLITLTWIGG | ||||||
Transmembrane | 347-367 | Helical | ||||
Sequence: SIIIGQLASILYFTLILVLMP |
Keywords
- Cellular component
PTM/Processing
Features
Showing features for chain.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Chain | PRO_0000254862 | 1-381 | Cytochrome b | |||
Sequence: MINLRKTHPLMKIINHSFIDLPAXSNISAWWNFGSSLGVCLMIQISTGLFLAMHYTSDTLTAFSSVAHICRDVNYGWIIRNLHANGASMFFMCLFLHIGRGIYYGSYLYKETWNIGVILLLTVMATAFVGYVLPWGQMSFWGATMVTNLLSAIPYIGTTLAEWIWGGFSVDKATLTRFFAFHFILPFIIMALVIVHLLFLQETGSNNPSGINPDSDKIPFHPYYTIKDALGLMFLLLVLLSLALFSPDLLGDPDNFSPANPLNTPPHIKPEWYFLFAYAILRSIPNKLGGVLALLASILILLVIPFLHTANQRSMMFRPISQTLFWILTANLITLTWIGGQPVEQPSIIIGQLASILYFTLILVLMPLAGMFENYMLEPKW |
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
- Length381
- Mass (Da)42,850
- Last updated1999-11-01 v1
- ChecksumCA9C81C2A9CD557B