Required for the insertion of integral membrane proteins into the mitochondrial inner membrane. Essential for the activity and assembly of cytochrome c oxidase. Plays a central role in the translocation and export of the C-terminal part of the COX2 protein into the mitochondrial intermembrane space. Interacts with PNT1 and MSS2. Present with 468 molecules/cell in log phase SD medium. Belongs to the OXA1/ALB3/YidC family.