Figure 2.

Phosphorylation of Spo0A increases the expression of ahpA. Shown are the expression levels of ahpA based on β‐galactosidase activity from a transcriptional fusion of the ahpA promoter to lacZ. The kinA gene was expressed from a P_spac promoter (p‐kinA). Strains were grown with aeration in LB broth at 37°C. At an OD ₆₀₀ of 0.4, 500 μmol/L IPTG was added to the indicated cultures (t = 0 hr). Samples were taken at 0, 1, and 2 hr postinduction. (A) Expression level of ahpA after induction of kinA. “Wild type” represents a strain containing the lacZ fusion but lacking the p‐kinA construct. Error bars indicate the standard error for three independent cultures. (B) Fold change in β‐galactosidase activity from the ahpA'‐lacZ fusion resulting from the induction of kinA in strains lacking katX compared to isogenic strains containing wild‐type katX (ΔkatX/wild type)