O79465 · CYB_SORTR

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.

Caution

The full-length protein contains only eight transmembrane helices, not nine as predicted by bioinformatics tools.

Cofactor

heme b (UniProtKB | Rhea| CHEBI:60344 )

Note: Binds 2 heme b groups non-covalently.

Features

Showing features for binding site.

137950100150200250300350
TypeIDPosition(s)Description
Binding site83Fe (UniProtKB | ChEBI) of heme b b562 (UniProtKB | ChEBI); axial binding residue
Binding site97Fe (UniProtKB | ChEBI) of heme b b566 (UniProtKB | ChEBI); axial binding residue
Binding site182Fe (UniProtKB | ChEBI) of heme b b562 (UniProtKB | ChEBI); axial binding residue
Binding site196Fe (UniProtKB | ChEBI) of heme b b566 (UniProtKB | ChEBI); axial binding residue
Binding site201a ubiquinone (UniProtKB | ChEBI)

GO annotations

AspectTerm
Cellular Componentmitochondrial inner membrane
Cellular Componentrespiratory chain complex III
Molecular Functionmetal ion binding
Molecular Functionubiquinol-cytochrome-c reductase activity
Biological Processmitochondrial electron transport, ubiquinol to cytochrome c

Keywords

Names & Taxonomy

Protein names

  • Recommended name
    Cytochrome b
  • Alternative names
    • 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 names

  • Taxonomic identifier
  • Strain
    • Isolate AFTC 14146
  • Taxonomic lineage
    Eukaryota > Metazoa > Chordata > Craniata > Vertebrata > Euteleostomi > Mammalia > Eutheria > Laurasiatheria > Eulipotyphla > Soricidae > Soricinae > Sorex

Accessions

  • Primary accession
    O79465
  • Secondary accessions
    • O79466
    • Q8SFK4

Subcellular Location

Features

Showing features for transmembrane.

TypeIDPosition(s)Description
Transmembrane33-53Helical
Transmembrane77-98Helical
Transmembrane113-133Helical
Transmembrane178-198Helical
Transmembrane226-246Helical
Transmembrane288-308Helical
Transmembrane320-340Helical
Transmembrane347-367Helical

Keywords

Phenotypes & Variants

Features

Showing features for natural variant.

TypeIDPosition(s)Description
Natural variant262
Natural variant276
Natural variant292
Natural variant348
Natural variant353

Variants

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The viewer provides 5 variants from UniProt as well as other sources including ClinVar and dbSNP.

Go to variant viewer

PTM/Processing

Features

Showing features for chain.

TypeIDPosition(s)Description
ChainPRO_00000615831-379Cytochrome b

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

Family & Domains

Sequence similarities

Belongs to the cytochrome b family.

Keywords

Family and domain databases

Sequence

  • Sequence status
    Complete
  • Length
    379
  • Mass (Da)
    42,657
  • Last updated
    2003-04-23 v2
  • Checksum
    DA9443925AEA3750
MTNLRKTHPLMKIVNSSFIDLPTPSNISSWWNFGSLLGICLIVQILTGLFLAMHYTSDTLTAFSSVTHICRDVNYGWLIRYMHANGASMFFICLFMHVGRGIYYGSYMFLETWNIGVLLLFAVMATAFMGYVLPWGQMSFWGATVITNLLSAIPYIGTDLVEWIWGGFSVDKATLTRFFAFHFILPFIVAALAGVHLLFLHETGSNNPSGLSSDADKIPFHPYYTIKDILGVLLFILVLTSLVLFSPDLLGDPDNYTPANPLNTPPHIKPEWYFLFAYAILRSIPNKLGGVLALVLSILVLAVIPFLHTSKQRSMMFRPLSQCLFWILVADLLTLTWIGGQPVEHPFIIIGQLASILYFLLILVLMPITSLFENNLLKW

Features

Showing features for sequence conflict.

TypeIDPosition(s)Description
Sequence conflict189in Ref. 2; CAA04106/CAA04107

Sequence databases

Nucleotide SequenceProtein SequenceMolecule TypeStatus
AY014956
EMBL· GenBank· DDBJ
AAG40515.1
EMBL· GenBank· DDBJ
Genomic DNA
AJ000463
EMBL· GenBank· DDBJ
CAA04106.1
EMBL· GenBank· DDBJ
Genomic DNA
AJ000464
EMBL· GenBank· DDBJ
CAA04107.1
EMBL· GenBank· DDBJ
Genomic DNA

Similar Proteins

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