This component is a heteromeric complex consisting of 3 catalytic subunits encoded by mitochondrial genes and multiple structural subunits encoded by nuclear genes. The mitochondrially encoded subunits function in electron transfer, and the nuclear-encoded subunits may function in the regulation and assembly of the complex. This nuclear gene encodes polypeptide 2 (liver isoform) of subunit VIIa and the polypeptide 2 is present in both muscle and nonmuscle tissues.
In addition to polypeptide 2, subunit VIIa includes polypeptide 1 (muscle isoform), which is present only in muscle tissues, and a related protein, present in all tissues. This gene may have several pseudogenes.[7]
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^"Mouse PubMed Reference:". National Center for Biotechnology Information, U.S. National Library of Medicine.
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^Merante F, Duncan AM, Mitchell G, Duff C, Rommens J, Robinson BH (Aug 1997). "Chromosomal localization of the human liver form cytochrome c oxidase subunit VIIa gene". Genome. 40 (3): 318–24. doi:10.1139/g97-044. PMID9202412.
Lenka N, Vijayasarathy C, Mullick J, Avadhani NG (1998). "Structural Organization and Transcription Regulation of Nuclear Genes Encoding the Mammalian Cytochrome c Oxidase Complex". Prog. Nucleic Acid Res. Mol. Biol. Progress in Nucleic Acid Research and Molecular Biology. 61: 309–44. doi:10.1016/S0079-6603(08)60830-2. ISBN978-0-12-540061-9. PMID9752724.
Van Kuilenburg AB, Van Beeumen JJ, Van der Meer NM, Muijsers AO (1992). "Subunits VIIa,b,c of human cytochrome c oxidase. Identification of both 'heart-type' and 'liver-type' isoforms of subunit VIIa in human heart". Eur. J. Biochem. 203 (1–2): 193–9. doi:10.1111/j.1432-1033.1992.tb19847.x. PMID1309697.
Taanman JW, Hall RE, Tang C, et al. (1993). "Tissue distribution of cytochrome c oxidase isoforms in mammals. Characterization with monoclonal and polyclonal antibodies". Biochim. Biophys. Acta. 1225 (1): 95–100. doi:10.1016/0925-4439(93)90128-n. PMID8241294.
Merante F, Ling M, Duncan AM, et al. (1997). "Cloning, characterization, and chromosomal localization of human liver form cytochrome c oxidase subunit VIa related genes". Genome. 40 (3): 325–31. doi:10.1139/g97-045. PMID9202413.
Hüttemann M, Mühlenbein N, Schmidt TR, et al. (2000). "Isolation and sequence of the human cytochrome c oxidase subunit VIIaL gene". Biochim. Biophys. Acta. 1492 (1): 252–8. doi:10.1016/s0167-4781(00)00087-7. PMID11004498.