FIG 4.

FFA-mediated in vitro inhibition of the PrfA*-phly complex formation. (A and B) EMSAs of PrfA*-phly interaction. Labeled phly was tested for its ability to interact with increasing concentrations of purified PrfA* protein (His-tagged PrfA-G145S) in the absence (Control) or presence of 256 μM LA, MA, PAL, or SA (A) or 256 μM of GLA, LNA, LLA, OA, or EA (B). The fraction of unbound phly is shown below each lane. (C and D) Titration EMSAs of LA and SA. (C) Increasing concentrations of LA or SA were added to constant amounts of PrfA* and phly. The fraction of unbound phly is shown below each lane. (D) Unbound phly at each LA or SA concentration was used to draw a dose-response inhibition curve to obtain the concentration of LA or SA required to disrupt 50% of the already formed PrfA*-phly complex (IC₅₀).