[12][13][14] Diseases caused by defects of mitochondrial carriers are reviewed by Palmieri et al. (2008) and by Gutiérrez-Aguilar and Baines 2013.

[17] This event may have occurred less than 2 billion years ago when mitochondria first developed their specialized endosymbiotic functions within eukaryotic cells.

[3][4] Most MC proteins contain a primary structure exhibiting three repeats, each of about 100 amino acid residues in length, and both the N and C termini face the intermembrane space.

[19] The AAC is an integral membrane protein that is synthesised lacking a cleavable presequence, but instead contains internal targeting information.

[20] It consists of a basket-shaped structure with six transmembrane helices that are tilted with respect to the membrane, 3 of them "kinked" due to the presence of prolyl residues.

By scoring the symmetry of residues in the sequence repeats, Robinson et al. (2008) identified the substrate-binding sites and salt bridge networks that are important for transport.

The symmetry analyses provides an assessment of the role of residues and provides clues to the chemical identities of substrates of uncharacterized transporters.

[29] The transported substrates of MC family members may bind to the bottom of the cavity, and translocation results in a transient transition from a 'pit' to a 'channel' conformation.