FIGURE 7.

PhoP regulates expression of pks2 and msl3 by specific recognition of direct repeat motif. To examine the importance of predicted PhoP-binding sites in PhoP-dependent transcription regulation of pks2 and msl3, M. smegmatis strains harboring pks2up1sDR2 (A) and msl3up1sDR2 (B) (see “Results” for details), as well as the corresponding wild-type regulatory regions, were grown in the absence or presence of inducing PhoP expression as indicated on the figure and described in the legends to Fig. 3. β-Galactosidase activity from the transcription fusion was measured at indicated times. Insets compare expression of PhoP in crude extracts (24-h time point) containing equal amounts of total protein by Western blot using anti-PhoP antibody (Abexome Biosciences). As loading control, crude extracts were probed with antibody against β-subunit of RNA polymerase (Abcam).