Figure 2.

Involvement of AhrC in Mn²⁺transporter genes expression by EMSA. (A) EMSA. Protein concentrations and probe names are shown. Numbers in parentheses show nucleotides position to the relative to the translation start point for argC and thiL. For the others, numbers in parentheses show nucleotides position to the relative to the transcription start point. (B) and left panel in (C) representsβ-Galactosidase activities. Substrate used was 2-Nitrophenyl-β-D-Galactopyranoside for mntH-lacZ and CPRG for the others. Significant differences in the effects of glucose addition at T2 (T1 for mntA-lacZ) were determined using nonpaired t test. ∗p < 0.05; NS, no significant differences. The x-axis represents the growth time in hours relative to the end of vegetative growth (T0). Cells were grown in sporulation medium with (closed symbols) or without (open symbols) 2% glucose and sampled hourly. Strains: PmneP-lacZ (wt, OAM1016; ahrC, OAM1020), PmneS-lacZ (wt, OAM1017; ahrC, OAM1021), PmntA-lacZ (wt, OAM1014; ahrC, OAM1018; ccpN, OAM1024). Schematic representation of the structure of the PmntH-lacZ fusion is shown. Box, bent arrows, and stem–loop indicate ORF, promoter, and terminator, respectively. Right panel in (C) shows cellular Mn concentrations in the ccpN strain (OAM998). T2 cells grown in sporulation medium were harvested and processed. “Glu” represents glucose. Three biologically independent samples were measured. Significant differences between Wt and mutant, with or without glucose (∗ and “NS” above each data point indicate p < 0.05 and no significant difference, respectively) and the effect of glucose addition to the strain were determined using nonpaired t test. ∗p < 0.05; NS, no significant differences. The short horizontal lines indicate the mean of the data points. CPRG, chlorophenolred β-D-galactopyranoside.