P38594 · CYB_LEPWE

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 respiratory 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

Accessions

  • Primary accession
    P38594
  • Secondary accessions
    • Q08H98

Proteomes

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

PTM/Processing

Features

Showing features for chain.

TypeIDPosition(s)Description
ChainPRO_00000611161-379Cytochrome 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

Phylogenomic databases

Family and domain databases

Sequence

  • Sequence status
    Complete
  • Length
    379
  • Mass (Da)
    42,545
  • Last updated
    1994-10-01 v1
  • Checksum
    1B17CC1C2D2714B7
MTNIRKTHPLAKIINNSFIDLPTPSNISAWWNFGSLLGICLILQILTGLFLAMHYTSDTTTAFSSVTHICRDVNYGWIIRYMHANGASMFFICLYMHVGRGLYYGSYTFTETWNIGIILLFTVMATAFMGYVLPWGQMSFWGATVITNLLSAIPYIGTDLVQWIWGGFSVDKATLTRFFAFHFILPFVVSALAAVHLLFLHETGSNNPSGIPSDSDKIPFHPYYTIKDILGALLLILTLMLLVLFSPDLLGDPDNYTPANPLSTPPHIKPEWYFLFAYAILRSIPNKLGGVLALALSILILAIIPLLHTSKQRGMMFRPISQCLFWLLVADLLTLTWIGGQPVEHPYITIGQLASILYFTILLVLMPITSIIENNILKW

Keywords

Sequence databases

Nucleotide SequenceProtein SequenceMolecule TypeStatus
X72005
EMBL· GenBank· DDBJ
CAA50890.1
EMBL· GenBank· DDBJ
Genomic DNA
AM181025
EMBL· GenBank· DDBJ
CAJ57000.1
EMBL· GenBank· DDBJ
Genomic DNA
U12843
EMBL· GenBank· DDBJ
AAA67253.1
EMBL· GenBank· DDBJ
Genomic DNA

Genome annotation databases

Similar Proteins

Disclaimer

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