O79195 · CYB_APTPA

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 site84Fe (UniProtKB | ChEBI) of heme b b562 (UniProtKB | ChEBI); axial binding residue
Binding site98Fe (UniProtKB | ChEBI) of heme b b566 (UniProtKB | ChEBI); axial binding residue
Binding site183Fe (UniProtKB | ChEBI) of heme b b562 (UniProtKB | ChEBI); axial binding residue
Binding site197Fe (UniProtKB | ChEBI) of heme b b566 (UniProtKB | ChEBI); axial binding residue
Binding site202a 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
  • Strain
    • Isolate KingP-MI-1
  • Taxonomic lineage
    Eukaryota > Metazoa > Chordata > Craniata > Vertebrata > Euteleostomi > Archelosauria > Archosauria > Dinosauria > Saurischia > Theropoda > Coelurosauria > Aves > Neognathae > Sphenisciformes > Spheniscidae > Aptenodytes

Accessions

  • Primary accession
    O79195

Subcellular Location

Features

Showing features for transmembrane.

TypeIDPosition(s)Description
Transmembrane34-54Helical
Transmembrane78-99Helical
Transmembrane114-134Helical
Transmembrane179-199Helical
Transmembrane227-247Helical
Transmembrane289-309Helical
Transmembrane321-341Helical
Transmembrane348-368Helical

Keywords

PTM/Processing

Features

Showing features for chain.

TypeIDPosition(s)Description
ChainPRO_00000606121-380Cytochrome 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
    380
  • Mass (Da)
    42,564
  • Last updated
    1998-11-01 v1
  • Checksum
    D3A58E9249DB2F34
MAPNLRKSHPLLKMINNSLIDLPTPSNISAWWNFGSLLGICLTTQILTGLLLAMHYTADTTLAFSSVAHTCRNVQYGWLIRNLHANGASFFFICIYLHIGRGFYYGSYLYKETWNTGIILLLTLMATAFVGYVLPWGQMSFWGATVITNLFSAIPYIGQTLVEWAWGGFSVDNPTLTRFFALHFLLPFMIAGLTLIHLTFLHESGSNNPLGIVANSDKIPFHPYYSTKDTLGFALMLLPLTTLALFSPNLLGDPENFTPANPLVTPPHIKPEWYFLFAYAILRSIPNKLGGVLALAASVLILFLIPLLHKSKQRTMTFRPLSQLLFWTLVANLTILTWIGSQPVEHPFIIIGQLASLTYFTILLILFPLIGTLENKMLNH

Sequence databases

Nucleotide SequenceProtein SequenceMolecule TypeStatus
AF076044
EMBL· GenBank· DDBJ
AAC68601.1
EMBL· GenBank· DDBJ
Genomic DNA

Similar Proteins

Disclaimer

Any medical or genetic information present in this entry is provided for research, educational and informational purposes only. It is not in any way intended to be used as a substitute for professional medical advice, diagnosis, treatment or care. Our staff consists of biologists and biochemists that are not trained to give medical advice.
We'd like to inform you that we have updated our Privacy Notice to comply with Europe’s new General Data Protection Regulation (GDPR) that applies since 25 May 2018.
FeedbackHelp