FIGURE 5.

Effects of manganese and iron on mntH and irr expression in the wild type and irr mutant and on Fur occupancy of the mntH and irr promoters in those cells. A and B, steady state mRNA levels of the mntH or irr genes were analyzed by quantitative real-time PCR from cells grown with various iron and manganese conditions as described in Fig. 2. The data are expressed as the SQ of the respective mRNAs normalized to the housekeeping gene gapA and presented as the average triplicate samples plus the S.D. C and D, cross-linking and immunoprecipitation of wild type (Wt) or fur mutant were carried out as described in Fig. 2, but anti-Irr antibodies were used for the immunoprecipitation. The data are expressed as the SQ of immunoprecipitated DNA normalized to the mock pull down. norm, normalized.