The F0F1 ATP synthase is a large multisubunit complex that couples transloc
ation of protons down an electrochemical gradient to the synthesis of ATP.
Recent advances in structural analyses have led to the demonstration that t
he enzyme utilizes a rotational catalytic mechanism. Kinetic and biochemica
l evidence is consistent with the expected equal participation of the three
catalytic sites in the alpha(3)beta(3) hexamer, which operate in sequentia
l, cooperative reaction pathways. The rotation of the core gamma subunit pl
ays critical roles in establishing the conformation of the sites and the co
operative interactions. Mutational analyses have shown that the rotor subun
its are responsible for coupling and in doing so transmit specific conforma
tional information between transport and catalysis.