Figure 3.

Synthesis and hydrolysis of ATP catalyzed by two forms of F₁·F_o. The main components of a bacterial cell coupling membrane are shown. The proton motive force (pmf) is generated by the respiratory chain (RC). F₁∙F_o ATP synthase (blue) and ATP hydrolase (red) are composed of hydrophilic F₁ that performs the catalytic function, and F_o provides proton translocation. F_o acts as a mechanical driving device rotating the γ subunit of F₁. Venturicidin inhibition is also shown. Arrows in the centre indicate high affinity of ATP synthase (thick arrow) and low affinity of ATP hydrolase (thin arrow) for venturicidin.