Involved in mitochondrial RNA maturation and mitochondrial respiratory chain function. High expression in heart and liver and low expression in kidney, brain and testis. Deficient mice shown deficiency of the third complex of the respiratory chain that caused profound ultrastructural changes in the heart. The outer layers of ventricular cardiomyocytes appeared to be infiltrated with macrovesicular fat deposits, having the appearance of adipocytes. Belongs to the PTCD2 family. Contaminating sequence. Potential vector sequence.