Summary The Salmonella ugd gene is required for the incorporation of 4-aminoarabinose in the lipopolysaccharide and resistance to the antibiotic polymyxin B. Transcription of the ugd gene is induced by Fe3 + via the PmrA -- PmrB two-component system and by low Mg2 + in a process that requires the PhoP -- PhoQ two-component system , the PhoP-activated PmrD protein and the PmrA -- PmrB system .
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 ) .
b-Galactosidase activity ( Miller units ) expressed by strains grown in LB-medium was determined for strains harbouring lac transcriptional-fusions to the PhoP-activated PmrA-dependent ugd ( A -- C ) and pbgP ( A ) genes , and the PhoP-activated PmrA-independent mgtA gene ( A ) .
b-Galactosidase activity ( Miller units ) expressed by strains grown in LB-medium was determined for strains harbouring lac transcriptional-fusions to the PhoP-activated PmrA-dependent ugd ( A -- C ) and pbgP ( A ) genes , and the PhoP-activated PmrA-independent mgtA gene ( A ) .
D. Alignment of the regulatory sequences of the PhoP-activated ugd , phoP , mgtA and mgrB genes .
the PhoP-dependent conditions activate ugd expression in Salmonella
the PhoP-dependent conditions activate ugd expression in Salmonella
the PhoP-dependent conditions activate ugd expression in Salmonella
the PhoP-dependent conditions activate ugd expression in Salmonella