Component of the MICOS complex; MICOS (formerly MINOS or MitOS) is a mitochondrial inner membrane complex that extends into the intermembrane space and has a role in the maintenance of crista junctions, inner membrane architecture, and formation of contact sites to the outer membrane; negative regulator of Mic10p oligomerization; Mic26p is a non-essential component of the complex; orthologous to human APOO and APOOL