Cmc1 is a metallo-chaperone like protein which is known to localise to the inner mitochondrial membrane in Saccharomyces cerevisiae. It is essential for full expression of cytochrome c oxidase and respiration [1]. Cmc1 contains two Cx9C motifs and is able to bind copper(I). Cmc1 is thought to play a role in mitochondrial copper trafficking and transfer to cytochrome c oxidase [1].

1: Cmc1p is a Conserved Mitochondrial Twin Cx9C Protein Involved in Cytochrome c Oxidase Biogenesis. Horn D, Al-Ali H, Barrientos A; Mol Cell Biol. 2008; [Epub ahead of print] PMID:18443040