Channel-forming protein essential for import of protein precursors into mitochondria (PubMed:15644312, PubMed:31206022). Plays a role in the assembly of the mitochondrial membrane respiratory chain NADH dehydrogenase (Complex I) by forming a complex with BCAP31 and mediating the translocation of Complex I components from the cytosol to the mitochondria (PubMed:31206022).