InterPro : IPR013833

Name  Cytochrome c oxidase, subunit III, 4-helical bundle Short Name  Cyt_c_oxidase_su3_a-hlx
Type  Domain Description  Cytochrome c oxidase () is the terminal enzyme of the respiratory chain of mitochondria and many aerobic bacteria. It catalyzes the transfer of electrons from reduced cytochrome c to molecular oxygen:4 cytochrome c+2+ 4 H++ O2-->4 cytochrome c+3+ 2 H2OThis reaction is coupled to the pumping of four additional protons across the mitochondrial or bacterial membrane [, ]. Cytochrome c oxidase is an oligomeric enzymatic complex that is located in the mitochondrial inner membrane of eukaryotes and in the plasma membrane of aerobic prokaryotes. The core structure of prokaryotic and eukaryotic cytochrome c oxidase contains three common subunits, I, II and III. In prokaryotes, subunits I and III can be fused and a fourth subunit is sometimes found, whereas in eukaryotes there are a variable number of additional small polypeptidic subunits []. The functional role of subunit III is not yet understood.Subunit III of cytochrome c oxidase has a core structure consisting of 6-7 transmembrane alpha-helices organised into two bundles, one bundle formed by the first two helices and the other by the remaining helices. This entry represents the 4-5 alpha-helical bundle.

Sequence Features

GO Displayer


InterPro protein domain ID --> Contigs



0 Child Features

0 Contains

2 Found In

Id Name Short Name Type
IPR014206 Cytochrome o ubiquinol oxidase, subunit III Cyt_c_ubiqinol_oxidase_su3 Family
IPR014246 Quinol oxidase subunit III QoxC Family

0 Parent Features

3 Publications

First Author Title Year Journal Volume Pages
Michel H Cytochrome c oxidase: catalytic cycle and mechanisms of proton pumping--a discussion. 1999 Biochemistry 38 15129-40
Mather MW Cytochrome oxidase genes from Thermus thermophilus. Nucleotide sequence of the fused gene and analysis of the deduced primary structures for subunits I and III of cytochrome caa3. 1993 J Biol Chem 268 5395-408
Belevich I Proton-coupled electron transfer drives the proton pump of cytochrome c oxidase. 2006 Nature 440 829-32

To cite PlanMine, please refer to the following publication:

Rozanski, A., Moon, H., Brandl, H., Martín-Durán, J. M., Grohme, M., Hüttner, K., Bartscherer, K., Henry, I., & Rink, J. C.
PlanMine 3.0—improvements to a mineable resource of flatworm biology and biodiversity
Nucleic Acids Research, gky1070. doi:10.1093/nar/gky1070 (2018)