COX5A

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Identifiers
Aliases
External IDs	GeneCards: [1]
Orthologs
Species	Human	Mouse
Entrez	n/a	n/a
Ensembl	n/a	n/a
UniProt	n/a	n/a
RefSeq (mRNA)	n/a	n/a
RefSeq (protein)	n/a	n/a
Location (UCSC)	n/a	n/a
PubMed search	n/a	n/a
Wikidata
View/Edit Human

Cytochrome c oxidase subunit 5a is a protein that in humans is encoded by the COX5A gene. Cytochrome c oxidase 5A is a subunit of the cytochrome c oxidase complex, also known as Complex IV, the last enzyme in the mitochondrial electron transport chain.

Structure

The COX5A gene, located on the q arm of chromosome 15 in position 24.1, is made up of 5 exons and is 17,880 base pairs in length. The COX5A protein weighs 17 kDa and is composed of 150 amino acids. The protein is a subunit of Complex IV, which consists of 13 mitochondrial- and nuclear-encoded subunits.

Function

Cytochrome c oxidase (COX) is the terminal enzyme of the mitochondrial respiratory chain. It is a multi-subunit enzyme complex that couples the transfer of electrons from cytochrome c to molecular oxygen and contributes to a proton electrochemical gradient across the inner mitochondrial membrane to drive ATP synthesis via protonmotive force. The mitochondrially-encoded subunits perform the electron transfer of proton pumping activities. The functions of the nuclear-encoded subunits are unknown but they may play a role in the regulation and assembly of the complex.

Summary reaction:

4 Fe²⁺-cytochrome c + 8 H⁺_in + O₂ → 4 Fe³⁺-cytochrome c + 2 H₂O + 4 H⁺_out

Clinical significance

COX5A (this gene) and COX5B are involved in the regulation of cancer cell metabolism by Bcl-2. COX5A interacts specifically with Bcl-2, but not with other members of the Bcl-2 family, such as Bcl-xL, Bax or Bak.

The Trans-activator of transcription protein (Tat) of human immunodeficiency virus (HIV) inhibits cytochrome c oxidase (COX) activity in permeabilized mitochondria isolated from both mouse and human liver, heart, and brain samples.

Further reading

• Williams SL, Valnot I, Rustin P, Taanman JW (Feb 2004). "Cytochrome c oxidase subassemblies in fibroblast cultures from patients carrying mutations in COX10, SCO1, or SURF1". The Journal of Biological Chemistry. 279 (9): 7462–9. doi:10.1074/jbc.M309232200. PMID 14607829.
• Hughes GJ, Frutiger S, Paquet N, Pasquali C, Sanchez JC, Tissot JD, Bairoch A, Appel RD, Hochstrasser DF (Nov 1993). "Human liver protein map: update 1993". Electrophoresis. 14 (11): 1216–22. doi:10.1002/elps.11501401181. PMID 8313870.
• Kovalyov LI, Shishkin SS, Efimochkin AS, Kovalyova MA, Ershova ES, Egorov TA, Musalyamov AK (Jul 1995). "The major protein expression profile and two-dimensional protein database of human heart". Electrophoresis. 16 (7): 1160–9. doi:10.1002/elps.11501601192. PMID 7498159.
• Yano M, Ueta Y, Murasaki A, Kanda H, Oka C, Kawaichi M (Aug 2004). "Binding of proteins to the PDZ domain regulates proteolytic activity of HtrA1 serine protease". The Biochemical Journal. 381 (Pt 3): 895–904. doi:10.1042/BJ20040435. PMC 1133901. PMID 15101818.
• Hofmann S, Lichtner P, Schuffenhauer S, Gerbitz KD, Meitinger T (1998). "Assignment of the human genes coding for cytochrome c oxidase subunits Va (COX5A), VIc (COX6C) and VIIc (COX7C) to chromosome bands 15q25, 8q22-->q23 and 5q14 and of three pseudogenes (COX5AP1, COX6CP1, COX7CP1) to 14q22, 16p12 and 13q14-->q21 by FISH and radiation hybrid mapping". Cytogenetics and Cell Genetics. 83 (3–4): 226–7. doi:10.1159/000015185. PMID 10072584.
• Cornelis MC, Monda KL, Yu K, Paynter N, Azzato EM, Bennett SN, Berndt SI, Boerwinkle E, Chanock S, Chatterjee N, Couper D, Curhan G, Heiss G, Hu FB, Hunter DJ, Jacobs K, Jensen MK, Kraft P, Landi MT, Nettleton JA, Purdue MP, Rajaraman P, Rimm EB, Rose LM, Rothman N, Silverman D, Stolzenberg-Solomon R, Subar A, Yeager M, Chasman DI, van Dam RM, Caporaso NE (Apr 2011). "Genome-wide meta-analysis identifies regions on 7p21 (AHR) and 15q24 (CYP1A2) as determinants of habitual caffeine consumption". PLoS Genetics. 7 (4): e1002033. doi:10.1371/journal.pgen.1002033. PMC 3071630. PMID 21490707.
• Rizzuto R, Nakase H, Zeviani M, DiMauro S, Schon EA (Sep 1988). "Subunit Va of human and bovine cytochrome c oxidase is highly conserved". Gene. 69 (2): 245–56. doi:10.1016/0378-1119(88)90435-0. PMID 2853101.

External links

• Human COX5A genome location and COX5A gene details page in the UCSC Genome Browser.
• Mass spectrometry characterization of COX5A at COPaKB

This article incorporates text from the United States National Library of Medicine, which is in the public domain.