FIGURE 1: The mitochondrial contact site and cristae organizing system (MICOS) is required for the formation and stability of crista junctions of the inner mitochondrial membrane. Its core component Mic10 interacts with the F₁F_o-ATP synthase whose dimeric and oligomeric forms localize to strongly curved cristae tips and tubules. MICOS and the ATP synthase may associate via Mic10 at crista junctions (right), or a subpopulation of Mic10 may interact with the ATP synthase in cristae membranes (left). OM: outer membrane, IMS: intermembrane space, IBM: inner boundary membrane, TOM: translocase of the outer membrane, SAM: sorting and assembly machinery, C II / III / IV: complexes II, III and IV of the respiratory chain.