Figure 1. Overall structure of the F_O complex.

A, Cartoon for the ATP synthase dimer with subunits found in the F_O region outlined in black. B, The detergent glyco-diosgenin (GDN) extracts dimeric S. cerevisiae ATP synthase from mitochondrial membranes intact (left) or as the F_O complex after sodium bromide treatment of the membranes (right). Scale bar, 25 Å. C, Example of map density that allowed construction of an atomic model (subunit a, residues A168 to F196 and P212 to L242). Scale bars, 5 Å. Top (D) and side (E) views of the F_O dimer reveal the arrangement of subunits. One monomer is outlined with a dashed line in part D. Scale bar, 25 Å.