FIG. 5.

High-resolution AFM of the S. elongatus SAG 89.79 c ring. (A) Topograph showing the densely packed c-ring assembly after its reconstitution into the lipid bilayer. The wide and narrow ends of c rings suggest their alternating orientations in the membrane. (B) Gallery of single rings showing their c-subunit arrangements and stoichiometries. (C) Reference-free single-particle average of c rings (n = 131). Independent of the classes found by averaging, the ring stoichiometry was always 13. Topographs were recorded in buffer solution and exhibited gray levels corresponding to a vertical scale of 2.0 nm.