Component of the MICOS complex, a large protein complex of the mitochondrial inner membrane that plays crucial roles in the maintenance of crista junctions, inner membrane architecture, and formation of contact sites to the outer membrane. Plays a role in keeping cristae membranes connected to the inner boundary membrane. Also promotes protein import via the mitochondrial intermembrane space assembly (MIA) pathway (By similarity). Component of the mitochondrial contact site and cristae organizing system (MICOS) complex. Belongs to the MICOS complex subunit Mic60 family.