Cytochrome c oxidase subunit II C-terminal (IPR002429)

Short name: Cyt_c_oxidase_su2_C

Domain relationships

  • Cupredoxin (IPR008972)
    • Cytochrome c oxidase subunit II C-terminal (IPR002429)


Cytochrome c oxidase (EC: [PMID: 6307356, PMID: 8083153] is an oligomeric enzymatic complex which is a component of the respiratory chain and is involved in the transfer of electrons from cytochrome c to oxygen. In eukaryotes this enzyme complex is located in the mitochondrial inner membrane; in aerobic prokaryotes it is found in the plasma membrane. The number of polypeptides in the complex ranges from 3-4 (prokaryotes), up to 13(mammals). In Archaea, a cytochrome-c-type oxidase from Natronobacterium (cytochrome ba3) has been shown to consists of four subunits [PMID: 9428682].

Subunit 2 (CO II) transfers the electrons from cytochrome c to the catalytic subunit 1. It contains two adjacent transmembrane regions in its N terminus and the major part of the protein is exposed to the periplasmic or to the mitochondrial intermembrane space, respectively. CO II provides the substrate-binding site and contains a copper centre called Cu(A), probably the primary acceptor in cytochrome c oxidase. An exception is the corresponding subunit of the cbb3-type oxidase which lacks the copper A redox-centre. Several bacterial CO II have a C-terminal extension that contains a covalently bound haem c.

GO terms

Biological Process

No terms assigned in this category.

Molecular Function

GO:0005507 copper ion binding
GO:0004129 cytochrome-c oxidase activity

Cellular Component

GO:0016020 membrane

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.
PROSITE profiles