FIG. 4.
Activities of mutant promoter fragments in vitro with purified PvdS protein. (A) Purified hPvdS was incubated with core RNA polymerase and different plasmid templates as shown. Templates carried wild-type promoter fragments (pvdD [nucleotides −96 to +39] or pvdE-pvdF [−121 to +4 of pvdE and −92 to +34 of pvdF]) or mutations in the IS box of the pvdD promoter (pvdDmut), the pvdE-proximal IS box (mutE), or the pvdF-proximal IS box (mut F) (Fig. 1; Table 1); the mutation in the pvdD IS box is the same as that described previously (20). The rate of RNA production from each plasmid template was measured as described previously (27). Error bars indicate standard deviations. (B) Fold stimulation represents the ability of hPvdS to stimulate activity above that of core enzyme with a pvd promoter template minus the corresponding value obtained with a vector template, calculated using the following equation (2, 27): fold stimulation = [(hPvdS-core − hPvdS only)/core only]pUC::pvd template − [(hPvdS-core − hPvdS only)/core only]pUCvector template.