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. Component of the mitochondrial contact site and cristae organizing system (MICOS) complex, composed of at least MIC10, MIC12, MIC19, MIC26, MIC27 and MIC60. This complex was also known under the names MINOS or MitOS complex. Enriched at crista junctions. Increases frequency of mitochondrial genome loss. Partially altered shape of the mitochondrial network with condensed, fragmented mitochondria accumulating at the periphery of cells. 20-40% of mitochondria exhibit an increased inner membrane surface and stacks of lamellar cristae disconnected from the inner boundary membrane. Belongs to the apolipoprotein O/MICOS complex subunit Mic27 family.