Figure 2.

(A) TIRFM measurements of the intensities of YFP-FliG^WT subunits in otherwise CW-only tethered motors (in strains with fliG^CW on the genome and an IPTG-inducible vector carrying eyfp-fliG^WT). This particular measurement (n = 33 motors) was obtained at an IPTG concentration of 5 μM. (B) Mean YFP-FliG/FliG^Total fractions (from distributions of the sort shown in A) of YFP-FliG subunits incorporated in motors, shown as a function of inducer concentration. (C) CW_bias as a function of the fraction of FliG^CW in otherwise WT motors. Squares (circles) indicate experiments in which strains carried fliG^WT (fliG^CW) on the genome and a vector expressing fliG^CW (fliG^WT). No hysteresis in switch function is seen. The black curve is the model prediction for N = 26, E = 0.25, E_m = 0.45, and J = 1.9.