FIG. 2.

iraD::luxCDABE expression in strains affected for (p)ppGpp synthesis. Each data point is an average of four independent determinations. The variability is shown with error bars in both graphs. RLU, relative luminescence units (bioluminescence counts per minute, normalized to the OD₆₀₀). Wild-type, spoT(E319Q), and relA on the graph represent expression in the MG1655, spoT(E319Q), and relAΔ::FRT strains, respectively, and relA spoT represents expression in the ΔrelA ΔspoT double mutant. (A and B) Luciferase expression of the full-length iraD::luxCDABE fusion construct throughout growth. (C) Expression of a luciferase construct, fused to the −600 to −375 region of the iraD promoter containing the P1 start site at −417, throughout growth. (D) Expression of a luciferase construct, fused to the −262 to −1 region of the iraD upstream region containing the P2 start site at −137, throughout growth.