The leg-and-foot-shaped yE subunits stands firmly on the ring of c subunits The two b subunits of Fo seem to connect to the aB hexamer via the s subunit of f The proton channel is believed to lie between the a subunit and the ring of c subunits X-ray crystallography revealed that the three B subunits of f assumes three different conformations with bound ADP, ATP analog, or empty respectively (John Walker, 1994, Nature, 370: 621-628)• The leg-and-foot-shaped ge subunits stands firmly on the ring of c subunits. • The two b subunits of Fo seem to connect to the ab hexamer via the d subunit of F1 . • The proton channel is believed to lie between the a subunit and the ring of c subunits. • X-ray crystallography revealed that the three b subunits of F1 assumes three different conformations, with bound ADP, ATP analog, or empty respectively (John Walker, 1994, Nature, 370:621-628)!