Fig. 1.

Proposed chemomechanical coupling schemes of the (A) bacterial TF₁, (B) eukaryotic hMF₁, and (C) PdF₁. In all images, each circle represents the chemical state of the catalytic site in each β-subunit, the central red arrow represents the orientation of the γ-subunit, ATP* represents the prehydrolysis state of ATP, and 0° is defined as the ATP binding angle for the catalytic site at the 12 o’clock position. In C, dashed arrows indicate that the simultaneous release of P_i and ADP has not yet been precisely determined.