OXA1L/Oxa1 is a member of the conserved Oxa1/YidC/Alb3 protein family and is required for cytochrome c oxidase assembly. The OXA1L protein was initially identified in yeast proteins involved in the biogenesis of the mitochondrial respiratory chain complexes. It locates in the inner membrane of mitochondria and may be involved in mediating the insertion of proteins from the matrix into the inner membrane.