Fig. 7.

GUS activity in S. coelicolor M1152 derivatives containing the pspX promoter fused to gusA in the absence or presence of either pspX or pspXW transcribed from P_ermE*. P_ermE* fused to gusA was used as a positive control and the pspX promoter fused to gusA with no additional activator present as the negative control. (A) Spectrophotometric assay using the substrate p-nitrophenyl-β-d-glucoronide. Miller units are displayed per milligram of protein present in cell lysate. See Fig. 6 for the P_ermE*-gusA data. Error bars depict SD between three biological replicates. (B) Chromogenic assay on R2 agar containing the substrate 5-bromo-4-chloro-3-indolyl-β-d-glucoronide.