FIG 3.

Full-length WT and M103A ToxT degradation after shift to virulence-repressing conditions. (A) V. cholerae was grown under virulence-inducing conditions (LB, pH 6.5, 30°C, shaking) for 3 h while inducing WT ToxT or ToxT M103A from pBAD33. Samples were resuspended under virulence-repressing growth conditions (LB, pH 8.5, 37°C, shaking). Samples were normalized by OD₆₀₀, and equivalent culture volumes were taken at each time point to monitor degradation of full-length ToxT. Full-length ToxT migrates to ∼32 kDa (arrow). WT ToxT degradation over time is shown in lanes 2 to 5, and ToxT M103A degradation over time is shown in lanes 6 to 9. The blot shown is representative of at least 3 separate experiments. (B) Quantification of band intensities from Western blot in panel A was performed using ImageJ software. Graph represents the percentages of ToxT remaining after shift to virulence-repressing conditions compared to the amounts at time zero. WT ToxT was 82% degraded by 30 min after shift to virulence-repressing growth conditions, while ToxT M103A persisted to a greater extent.