Eukaryotic yeast V-ATPase rotary mechanism insights revealed by high-resolution single-molecule studies.

Vacuolar ATP-dependent proton pumps (V-ATPases) belong to a super-family of rotary ATPases and ATP synthases. The V complex consumes ATP to drive rotation of a central rotor that pumps protons across membranes via the V complex. Eukaryotic V-ATPases are regulated by reversible disassembly of subunit C, V without C, and V ATP hydrolysis is thought to generate an unknown rotary state that initiates regulated disassembly.

FF ATP synthase molecular motor mechanisms.

The F-ATP synthase, consisting of F and F motors connected by a central rotor and the stators, is the enzyme responsible for synthesizing the majority of ATP in all organisms. The F (αβ) ring stator contains three catalytic sites. Single-molecule F rotation studies revealed that ATP hydrolysis at each catalytic site (0°) precedes a power-stroke that rotates subunit-γ 120° with angular velocities that vary with rotational position.