Movie S2.

Opening and closure of the αEβE-interface associated with phosphate release and binding, respectively. The open and “closed” states are taken from the structures of F1-I3-ThioP and F1-ThioP, respectively. The αE- and βE-subunits are depicted in ribbon representation in red and yellow, respectively. To cycle continuously between the two states, select “Loop” in the “View” menu of QuickTime Player. Key structural elements associated with phosphate release and generation of rotation are identified in Fig. S4.