The binding change mechanism for the ATP synthase has two central features. One is that the principle use of energy required for ATP synthesis is to promote the release of tightly bound ATP and the binding of Pi and ADP in a manner competent to form bound ATP. The second is that during net ATP formation multiple catalytic sites on the synthase participate in strongly cooperative sequence. Rotation of the γ subunit in F₁ is thought to deform the catalytic sites to give binding change. When the crystal structure of the F₁-ATPase was eventually solved, direct evidences for rotation of subunits during catalysis of F₁-ATPase were provided.