Structure of the mitochondrial ATP synthase by electron cryomicroscopy

Abstract

We have determined the structure of intact ATP synthase from bovine heart mitochondria by electron cryomicroscopy of single particles. Docking of an atomic model of the F1-c10 subcomplex into a major segment of the map has allowed the 32 Å resolution density to be interpreted as the F1-ATPase, a central and a peripheral stalk and an F0 membrane region that is composed of two domains. One domain of F0 corresponds to the ring of c-subunits, and the other probably contains the a-subunit, the transmembrane portion of the b-subunit and the remaining integral membrane proteins of F0. The peripheral stalk wraps around the molecule and connects the apex of F1 to the second domain of F0. The interaction of the peripheral stalk with F 1-c10 implies that it binds to a non-catalytic α-β interface in F1 and its inclination where it is not attached to F1 suggests that it has a flexible region that can serve as a stator during both ATP synthesis and ATP hydrolysis.