Fig. 3.

Overall structure of the R-ADP and its asymmetry. (A) Overall structure of the R-ADP state viewed from (Left) the top and (Right) side. Seven subunits in one ring are colored in red, orange, yellow, green, cyan, blue, and purple. (B) Arrangement of (Left) equatorial, (Center) intermediate, and (Right) apical domains in the ring. E130 (in equatorial domain), V190 (in intermediate domain), and E310 (in apical domain) are connected (Cα values are shown as black spheres) to highlight the degree of asymmetry in different domains. (C) Numbers of intersubunit contacts between two neighboring subunits in the asymmetric R-ADP and symmetric T states. These contacts include salt bridges (<5 Å) and hydrogen bonds (<3.5 Å). Based on their locations, the contacts are categorized into three groups: between equatorial domains, between apical domains, and between intermediate apical domains.