Q36192 · CYB_URSAR

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.

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 Processrespiratory electron transport chain

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
  • Taxonomic lineage
    Eukaryota > Metazoa > Chordata > Craniata > Vertebrata > Euteleostomi > Mammalia > Eutheria > Laurasiatheria > Carnivora > Caniformia > Ursidae > Ursus

Accessions

  • Primary accession
    Q36192
  • Secondary accessions
    • Q36191
    • Q36193
    • Q36872
    • Q36938
    • Q36990
    • Q37052

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 variant57in lineages GB01, GB02, GB03, GB04 and GB05
Natural variant89in lineages GB01, GB02, GB03, GB04 and GB05
Natural variant110in lineages GB01, GB02, GB03, GB04, GB05, GB08, GB09, GB10, GB12, GB14 and GB17
Natural variant123in lineages GB01, GB02, GB03, GB04 and GB05
Natural variant153in lineages GB01, GB02, GB03 and GB05
Natural variant236in lineages GB01, GB02, GB03, GB04 and GB05
Natural variant238in lineages GB01, GB02, GB03, GB04 and GB05
Natural variant257in lineages GB01, GB02, GB03, GB04 and GB05
Natural variant303in lineages GB01, GB02, GB03, GB04 and GB05
Natural variant368in lineage GB01
Natural variant375in lineages GB10 and GB12

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.

Go to variant viewer

PTM/Processing

Features

Showing features for chain.

TypeIDPosition(s)Description
ChainPRO_00000617031-379Cytochrome 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)
    42,459
  • Last updated
    1997-11-01 v1
  • Checksum
    0D82449AD05FF329
MTNIRKTHPLAKIINNSFIDLPTPSNISAWWNFGSLLGVCLILQILTGLFLAMHYTPDTTTAFSSVTHICRDVHYGWVIRYVHANGASIFFICLFMHVGRGLYYGSYLFPETWNIGIILLFTIMATAFMGYVLPWGQMSFWGATVITNLLSAIPYIGTDLVEWIWGGFSVDKATLTRFFAFHFILPFIILALAAVHLLFLHETGSNNPSGIPSDSDKIPFHPYYTIKDILGALLLALTLATLVLFSPDLLGDPDNYTPANPLSTPPHIKPEWYFLFAYAILRSIPNKLGGVLALIFSILILAIIPLLHTSKQRGMMFRPLSQCLFWLLVADLLTLTWIGGQPVEHPFIIIGQLASILYFTILLVLMPIAGIIENNLLKW

Polymorphism

Sequenced in lineages GB01 to GB26.

Sequence databases

Nucleotide SequenceProtein SequenceMolecule TypeStatus
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

Similar Proteins

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