Molecular Architecture of the Rotary Motor in ATP Synthase

TLDR

ATP synthase contains a rotary motor driven by the proton‑motive force in its F₀ sector, which powers ATP synthesis by the F₁ domain. Electron‑density mapping of a yeast mitochondrial ATP synthase subcomplex revealed a ten‑subunit c ring of α‑helical hairpins whose interhelical loops contact the γ and δ stalk subunits, implying coordinated rotation of the ring and stalk during catalysis.

Abstract

Adenosine triphosphate (ATP) synthase contains a rotary motor involved in biological energy conversion. Its membrane-embedded F 0 sector has a rotation generator fueled by the proton-motive force, which provides the energy required for the synthesis of ATP by the F 1 domain. An electron density map obtained from crystals of a subcomplex of yeast mitochondrial ATP synthase shows a ring of 10 c subunits. Each c subunit forms an α-helical hairpin. The interhelical loops of six to seven of the c subunits are in close contact with the γ and δ subunits of the central stalk. The extensive contact between the c ring and the stalk suggests that they may rotate as an ensemble during catalysis.