FIG. 3.

OhrR can be inactivated by mixed disulfide formation with BSH after CHP treatment. OhrR binding to ohrA probe was detected using FA assay. Anisotropy was measured for the free probe (corresponding to 0 on the y axis) and after the addition of 300 nM of OhrR (corresponding to 1 on the y axis). Three micromolar CHP was added in the absence of thiol (△) or 10 μM (◯), 50 μM (★), 0.1 mM (×) 0.25 mM (▲), 0.5 mM (□), and 1 mM (◆) l-Cys (A) and BSH (B). Inactivation of WT OhrR by CHP treatment in the presence of BSH and restoration of DNA-binding activity by the addition of 10 mM DTT (times of addition are indicated by the arrows). BSH, bacillithiol; FA, fluorescence anisotropy.