FIG 2.

SavR and SavRS repress the expression of savRS. (A) The β-galactosidase activity driven by the savRS promoter in the WT and the savRS mutant strains. ****, P < 0.0001. (B) SavR bound to the promoter region of savRS. (C) SavRS bound to the promoter region of savRS. (D) The 18-bp recognition site for SavR in its own promoter region was identified by DNase I footprinting. (E) The 36-bp binding site for SavRS in the promoter region was identified by DNase I footprinting. The regions protected from DNase I digestion are marked by red boxes. The binding sequences are marked by red letters and black boxes. The locations of the long and short palindromes are marked by inverted arrows. (F) Determination of binding ability of SavR and SavRS with truncated probes by EMSA.