This is a family of proteins conserved from nematodes to humans. The function is not known. However, family members such as the import inner membrane translocase sub-unit Tim29 (C19orf52) found in human, is shown to be required for the stability of the TIM22 complex. TIM22 complex imports and inserts multi-pass trans-membrane proteins into the mitochondrial inner membrane by formation of a twin-pore translocase with components in the outer and inner membranes. TIM29 is integrated into the inner member with the C terminus exposed to the inter-membrane space and able to contact the translocase of the outer membrane. It is required for complex stability and for the addition of the TIMM22 protein to the complex [1].

1: Tim29 is a novel subunit of the human TIM22 translocase and is involved in complex assembly and stability. Kang Y, Baker MJ, Liem M, Louber J, McKenzie M, Atukorala I, Ang CS, Keerthikumar S, Mathivanan S, Stojanovski D; Elife. 2016; [Epub ahead of print] PMID:27554484