- Cytochrome c oxidase subunit II
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Cytochrome c oxidase subunit II, transmembrane domain 
Bacterial cytochrome c oxidase complex. Subunit II indicated by blue. Identifiers Symbol COX2_TM Pfam PF02790 InterPro IPR011759 PROSITE PDOC00075 SCOP 1occ TCDB 3.D.4 OPM family 4 OPM protein 1v55 Available protein structures: Pfam structures PDB RCSB PDB; PDBe PDBsum structure summary Cytochrome C oxidase subunit II, periplasmic domain Identifiers Symbol COX2 Pfam PF00116 InterPro IPR002429 PROSITE PDOC00075 SCOP 1occ TCDB 3.D.4 OPM family 4 OPM protein 1v55 Available protein structures: Pfam structures PDB RCSB PDB; PDBe PDBsum structure summary Cytochrome c oxidase subunit II, abbreviated CoxII, is the second subunit of cytochrome c oxidase.
Cytochrome c oxidase (EC 1.9.3.1)[1][2] 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 enzyme complex consists of 3-4 subunits (prokaryotes) to up to 13 polypeptides (mammals). In Leigh's disease, there may be an abnormality or deficiency of cytochrome oxidase.
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) (see IPR001505), 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.
The N-terminal domain of cytochrome C oxidase contains two transmembrane alpha-helices.
Human proteins containing this domain
COII; COX2; MT-CO2;
References
- ^ Capaldi RA, Malatesta F, Darley-Usmar VM (1983). "Structure of cytochrome c oxidase". Biochim. Biophys. Acta 726 (2): 135–148. PMID 6307356.
- ^ Rumbley J, Gennis RB, Garcia-Horsman JA, Barquera B, Ma J (1994). "The superfamily of heme-copper respiratory oxidases". J. Bacteriol. 176 (18): 5587–5600. PMC 196760. PMID 8083153. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=196760.
Further Reading
- The whole structure of the 13-subunit oxidized cytochrome c oxidase at 2.8 A. Tsukihara T, Aoyama H, Yamashita E, Tomizaki T, Yamaguchi H, Shinzawa-Itoh K, Nakashima R, Yaono R, Yoshikawa S; Science 1996;272:1136-1144. PubMed
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