FIG. 6.

Dephosphorylation of phospho-PhoP_His by the PhoQ-T48X proteins. [³²P]phospho-PhoP_His was prepared and purified as described in Materials and Methods. Purified [³²P]phospho-PhoP_His was incubated with either control membranes lacking PhoQ (Ctl.) or membranes containing PhoQ-T48X proteins. At indicated time points, aliquots (15 μl) were removed and reactions were stopped by the addition of Laemmli SDS sample buffer. Aliquots were subjected to SDS-PAGE. The amount of ³²P associated with the PhoP protein was determined with a PhosphorImager. WT, wild type.