FIG. 1.

Induced expression of S. dysenteriae ryhB results in increased sensitivity to paraquat and decreased secretion of Ipa protein. (A) Real-time PCR analysis of mxiE mRNA levels in S. dysenteriae wild-type strain ND100 carrying the vector control and pryhB. All values were normalized to the level of rrsA mRNA in each sample, and the results are expressed relative to the value obtained for the strain carrying the vector control. The data are the averages of three independent experiments, and the error bars represent one standard deviation. (B) SDS-PAGE analysis of proteins secreted by an equivalent number of S. dysenteriae wild-type strain ND100 cells containing the vector control (lane 1) or pryhB (lane 2). The arrow indicates the location of IpaC as determined by Western blotting. All assays were carried out following growth of each strain in the presence of 200 μM IPTG to induce expression of ryhB from pryhB.