FIGURE 2.

A, qRT-PCR analysis of the RNA levels of CysH, MetB, MetN, and FecD at the indicated concentration of HOCl. WT (open symbols) and yjiE⁻ cells (closed symbols) were grown at 37 °C and supplemented with HOCl. After 10 min, 5× concentrated LB was added to quench HOCl, cells were harvested, RNA was isolated, and the RNA levels were analyzed by qRT-PCR using specific primer pairs. Shown is the result of one representative experiment. Please note that CysH, MetB, and MetN are up-regulated, whereas FecD is down-regulated. B, analysis of intracellular free iron levels in WT and yjiE⁻ cells. Cells were cultivated in LB medium at 37 °C without stress (white bars) or subjected to stress (2.75 mm HOCl, 10 min; striped bars) and prepared for EPR analysis. Shown is the mean ± error from two to four independent experiments.