Fig. 4.

YdcR activates the expression of srfN at the transcriptional level. A, β-Galactosidase activity in the wild-type and ΔydcR mutant strains harboring a plasmid encoding lacZ fusion with the promoter region of srfN. β-Galactosidase activities from three independent measurements are shown with values normalized to that of the wild-type strain. B, β-Galactosidase activity assays were performed with the ΔydcR mutant strain harboring a plasmid encoding a lacZ fusion with the promoter region of srfN and complemented with a plasmid-encoded copy of ydcR or empty vector, under noninducing (no arabinose) or inducing (with 0.2% arabinose) conditions as indicated. β-Galactosidase activities from three independent measurements are shown with values normalized to that of the ΔydcR strain complemented with an empty plasmid under noninducing conditions. Asterisks indicate significant differences (***, p < 0.001).