e The leg-and-foot-shaped yc subunits stands firmly on the ring of c subunits e The two b subunits of f seem to connect to the aB hexamer via the 8 subunit ofFI e The proton channel is believed to lie between the a subunit and the ring of c subunits e 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)!