FIG 4.

Effect of TO and analogs on the ATP synthase activity of S. aureus. (A) Relative ATP synthase activity of the SCV ΔhemB strain in the presence of various inhibitors. The control (CTRL) represents the maximal ATP production in the absence of ATP synthase inhibitor whereas the assay performed without addition of NADH represents the minimal value. nd, not determined. (B) Relative ATP synthase activity of the SCV ΔhemB atpE mutants (SaR1, SaR4, SaR5, and SaR6) in the presence of TO. The effects of TO on the parental ΔhemB strain and the prototypical strain Newbould (WT) and on human mitochondria are also shown for comparison. (C) Correlation between TO and analogs (FcM, Fcm, FC02-190, and FC04-116). Log₂ MICs and the log₁₀ IC₅₀s were determined in the ATP synthase assay using S. aureusΔhemB membrane vesicles. (D) ATP production (relative light units, RLU) by membrane vesicles prepared from the SCV ΔhemB atpE mutants. ATP production by the parental ΔhemB strain and the prototypical strain Newbould (WT) is also shown. In panel D, letters shared between or among the groups indicate no significant difference.