FIG. 6.

High-affinity association between OmcA and MtrC. Fluorescence polarization changes (A) and associated binding isotherms (B) for purified FlAsH-labeled MtrC (0.5 μM) (see inset showing fluorescence in panel A) following titration with variable amounts of purified OmcA in 50 mM HEPES (pH 7.5) and 2% OGP and increasing amounts of KCl, which varied from 5 mM (▪) to 50 mM (□) to 100 mM (•) to 140 mM (○), and associated measured dissociation constants (C) were determined as described in Materials and Methods. Values are the averages and standard deviations of three independent measurements. mP, milli-polarization units.