The tolB effect appears to be specific to the ugd gene because transcription of the PhoP-activated PmrA-dependent pbgP gene and the PhoP-activated PmrA-independent mgtA gene was not affected by the tolB mutation regardless of the presence of functional phoP or pmrA genes ( Fig. 2A ; data not shown ) .
The tolB effect appears to be specific to the ugd gene because transcription of the PhoP-activated PmrA-dependent pbgP gene and the PhoP-activated PmrA-independent mgtA gene was not affected by the tolB mutation regardless of the presence of functional phoP or pmrA genes ( Fig. 2A ; data not shown ) .