Thermodynamic analyses of nucleotide binding to an isolated monomeric β subunit and the α3β3γ subcomplex of F1-ATPase.

Rotation of the γ subunit of the F1-ATPase plays an essential role in energy transduction by F1-ATPase. Hydrolysis of an ATP molecule induces a 120° step rotation that consists of an 80° substep and 40° substep. ATP binding together with ADP release causes the first 80° step rotation.