Conserved component of the MICOS complex; MICOS, a mitochondrial inner membrane (MIM) complex extends into the intermembrane space and maintains crista junctions, MIM architecture, and formation of contact sites to the outer membrane; homo-oligomerization is required for MIM bending leading to crista formation; oligomerization state regulated by Mic26p and Mic27p; forms a subcomplex with Mic12p and Mic27p whose assembly and stability requires cardiolipin;  ortholog of human MINOS1