THE ATP SYNTHASE - A SPLENDID MOLECULAR MACHINE

An X-ray structure of the F-1 portion of the mitochondrial ATP synthas e shows asymmetry and differences in nucleotide binding of the catalyt ic beta subunits that support the binding change mechanism with an int ernal rotation of the gamma subunit. Other structural and mutational p robes of the F-1 and F-0 portions of the ATP synthase are reviewed, to gether with kinetic and other evaluations of catalytic site occupancy and behavior during hydrolysis or synthesis of ATP. Subunit function a s related to proton translocation and rotational catalysis is consider ed. Physical demonstrations of the gamma subunit rotation have been ac hieved. The findings have implications for other enzymatic catalyses.