Pet100 is a chaperone required for the assembly of cytochrome c oxidase [1]. The human Pet100 homologue (also known as C19orf79) has been shown to be located in the mitochondrial inner membrane and forms a ~300 kDa subcomplex with mitochondrial complex IV subunits [2].

1: Structure and function of Pet100p, a molecular chaperone required for the assembly of cytochrome c oxidase in Saccharomyces cerevisiae. Forsha D, Church C, Wazny P, Poyton RO; Biochem Soc Trans. 2001;29:436-441. PMID:11498004

2: A founder mutation in PET100 causes isolated complex IV deficiency in Lebanese individuals with Leigh syndrome. Lim SC, Smith KR, Stroud DA, Compton AG, Tucker EJ, Dasvarma A, Gandolfo LC, Marum JE, McKenzie M, Peters HL, Mowat D, Procopis PG, Wilcken B, Christodoulou J, Brown GK, Ryan MT, Bahlo M, Thorburn DR; Am J Hum Genet. 2014;94:209-222. PMID:24462369