The molecular basis of mitochondrial crista formation by the MIC10 complex.

Mitochondrial cristae are essential for respiration, yet the molecular basis of how the high curvature of these membrane folds is maintained remains unclear. Using structure prediction tools and multiscale simulations, we examined the role of the MIC10 subcomplex of the mitochondrial contact site and cristae organizing system (MICOS). We found that the MIC10 proteins Mic10, Mic26, and Mic27 strongly recruit cardiolipin at conserved positive loop motifs, driving oligomerization of these subunits and resulting in the stabilization of curvature in model membranes. Reconstruction of the full MIC10 complex in a realistic crista junction setup shows its capability to maintain membrane bending, while intrinsically disordered regions may form a permeability barrier between cristae and the intermembrane space. These findings provide a mechanistic model for cristae curvature formation and suggest how MICOS components cooperate with cardiolipins to maintain mitochondrial architecture.