ATP synthase

Multiple rotational states of bacterial ATP synthase have been revealed by cryoelectron microscopy. The portion at the top (red) is a rotary motor powered by ATP, and the portion at the bottom is a motor that turns a cylindrical rotor (blue) using the flow of hydrogen ions through a stator subunit (magenta). By connecting these molecular machines together with an asymmetric axle (darker blue at center), one motor can drive the other, using flow of ions to make ATP, or by turning the other direction, using ATP to pump ions. PDB IDs: 6oqr, 6oqs, 6oqw, 6wnr, 6wnq, 6oqv.

Animation from Exploring the Structural Biology of Bioenergy.