Q20FR3 · CYB_LEPED

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
    Q20FR3

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_00002548091-379Cytochrome 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)
    42,659
  • Last updated
    2006-04-18 v1
  • Checksum
    C595CDFDD0F0E6CE
MTNIRKNHPLLKIINNSLIDLPTPPNISSLWNFGSLLGACLTIQIITGLFLAMHYTADTTTAFSSVTHICRDVNYGWTIRYLHANGASVFFLCLFIHVGRGLYYGSFTLLETWNVGIILLFSVMATAFMGYVLPWGQMSFWGATVITNLLSAIPYIGTDLVEWIWGGFSVSKATLTRFFALHFVLPFVILALVMIHLLFLHETGSNNPLGTSSNSDKIPFHPYYTTKDFLGLLLLILLLMVLTLFYPDLLGDPDNYSPANPLNTPPHIKPEWYFLFAYAILRSIPNKLGGVMALILSILILAIIPLLQPNKQQTMMFRPLSQFLFWILVADLLTLTWIGGQPVEDPFITIGQVASILYFLLMVLIMPTTCLIENKMLKW

Sequence databases

Nucleotide SequenceProtein SequenceMolecule TypeStatus
DQ109004
EMBL· GenBank· DDBJ
AAZ92434.1
EMBL· GenBank· DDBJ
Genomic DNA
DQ109005
EMBL· GenBank· DDBJ
AAZ92435.1
EMBL· GenBank· DDBJ
Genomic DNA
DQ109006
EMBL· GenBank· DDBJ
AAZ92436.1
EMBL· GenBank· DDBJ
Genomic DNA
DQ234888
EMBL· GenBank· DDBJ
ABB80437.1
EMBL· GenBank· DDBJ
Genomic DNA

Similar Proteins

Disclaimer

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