Complex III (cytochrome bc1) is a protein complex of the mitochondrial inner membrane that transfers electrons from ubiquinol to cytochrome c. UQCC3 functions in complex III assembly. The human UQCC3 is the ortholog of the fungal complex III assembly factor CBP4 [1]. It is also a potent antiviral protein independent of interferon production [2].

1: A mutation in the human CBP4 ortholog UQCC3 impairs complex III assembly, activity and cytochrome b stability. Wanschers BF, Szklarczyk R, van den Brand MA, Jonckheere A, Suijskens J, Smeets R, Rodenburg RJ, Stephan K, Helland IB, Elkamil A, Rootwelt T, Ott M, van den Heuvel L, Nijtmans LG, Huynen MA; Hum Mol Genet. 2014;23:6356-6365. PMID:25008109

2: Mitochondrial C11orf83 is a potent Antiviral Protein Independent of interferon production. Yang Y, Xiong S, Cai B, Luo H, Dong E, Li Q, Ji G, Zhao C, Wen Y, Wei Y, Yang H; Sci Rep. 2017;7:44303. PMID:28418037

3: C11orf83, a mitochondrial cardiolipin-binding protein involved in bc1 complex assembly and supercomplex stabilization. Desmurs M, Foti M, Raemy E, Vaz FM, Martinou JC, Bairoch A, Lane L; Mol Cell Biol. 2015;35:1139-1156. PMID:25605331