Fig. 5. Inhibition of the ATP synthase by oligomycin.

(A) Model of oligomycin bound to the F_o. The electron density (shown at 4.5σ) fitted with a model of an oligomycin molecule (magenta) at 4 super-imposable positions on the c₁₀-ring. (B) Positions of residues in a-subunit at which replacements can confer resistance to oligomycin. The three residues, Ile161, Ser165, and Leu222, in a-subunit are positioned at the interface between subunits c¹c², and c³c⁴ and directly in line with c-Glu59 (Fig. 5, C and D). This position is precisely where oligomycin binds when the site is exposed to the membrane bilayer. (C) Side view of the residues in a-subunit. (D) Positions of residues in c-subunits that interact with oligomycin. The c-subunit residues colored orange (Ala56, Ala60, Leu63, Phe64) are a subset of residues that provide binding interactions with oligomycin (29). (Three of the c-chains are shaded darker grey.)