Kinetic ratchet mechanism of ATP synthase circumvents rectification trade-off for inhibiting futile ATP consumption

Adenosine triphosphate (ATP) has a central place of cellular energetics and is often referred to as the energy currency of cells. Hence, the suppression of futile ATP consumption, as well as the efficient ATP production, is demanded. The ATP synthase is the cellular ATP factory and synthesizes ATP molecules via rotational machinery. Our single-molecule experiments show that the F$_1$, the enzymatic core of the ATP synthase, implements a rectifier that inhibits futile ATP-hydrolytic rotations while keeping the ATP-synthetic rotations intact. A simple ratchet potential can rectify current but inherits a trade-off between the current and the rectification efficacy. Here, we demonstrate the novel but simple rectification mechanism of F$_1$ that circumvents this trade-off based on a kinetic asymmetry between different chemomechanical paths.