FIG. 4.

Effects of CRP and KdgR on setA and sgrS expression. (A) Cells were grown in LB to an OD₆₀₀ of ∼0.5, and 0.1% αMG was added to half of the cultures. β-Galactosidase activity was assayed 45 min after the addition of αMG. (B) Cells were grown in LB supplemented with 100 μg/ml ampicillin to an OD₆₀₀ of ∼0.5 and assayed for β-galactosidase activity. (C) Cells were grown in LB to an OD₆₀₀ of ∼0.5, and 0.001% αMG was added to half of the cultures. β-Galactosidase activity was assayed 45 min after the addition of αMG. (D) Cells were grown in LB supplemented with 100 μg/ml ampicillin to an OD₆₀₀ of ∼0.5 and assayed for β-galactosidase activity. The error bars indicate standard deviations from three independent experiments.