On the one hand , ugd expression is promoted in low Mg2 + in a process that requires the Mg2 + - responsive PhoP -- PhoQ two-component system , the PhoP-regulated shunt protein PmrD and the PmrA -- PmrB two-component system ( Kox et al. , 2000 ) .
The PhoP -- PhoQ -- PmrA -- PmrB pathway of ugd activation in macrophages may be the same as that taking 2 + place in low Mg , where the PhoP -- PhoQ system activates the PmrA -- PmrB system via the PhoP-regulated protein PmrD ( Fig. 1 ; Kox et al. , 2000 ) .
Boxed region indicates what was previously known about the regulation of ugd transcription by the PhoP -- PmrA -- PmrB systems before the studies .
Boxed region indicates what was previously known about the regulation of ugd transcription by the PhoP -- PhoQ -- PmrB systems before the studies .
For example , the ugd promoter of Salmonella ( Fig. 1B ) , but not of Escherichia coli , harbors a PhoP box that is located much further upstream from an RNA polymerase binding site than in other PhoP-regulated promoters ( Table 3 ) .
Despite the lack of conservation in this atypically located regulatory site , we demonstrated that the PhoP protein binds to the Salmonella ugd in-vitro , inactivation of the PhoP box in the ugd promoter abolishes Escherichia coli is unable to promote ugd transcription under the PhoP-dependent conditions -LRB- E.A.G. , unpublished results -RRB- .
Despite the lack of conservation in this atypically located regulatory site , we demonstrated that the PhoP protein binds to the Salmonella ugd in-vitro , inactivation of the PhoP box in the ugd promoter abolishes Escherichia coli is unable to promote ugd transcription under the PhoP-dependent conditions -LRB- E.A.G. , unpublished results -RRB- .
Despite the lack of conservation in this atypically located regulatory site , we demonstrated that the PhoP protein binds to the Salmonella ugd in-vitro , inactivation of the PhoP box in the ugd promoter abolishes Escherichia coli is unable to promote ugd transcription under the PhoP-dependent conditions -LRB- C. Mouslim , unpublished results -RRB- .
Despite the lack of conservation in this atypically located regulatory site , we demonstrated that the PhoP protein binds to the Salmonella ugd in-vitro , inactivation of the PhoP box in the ugd promoter abolishes Escherichia coli is unable to promote ugd transcription under the PhoP-dependent conditions -LRB- C. Mouslim , unpublished results -RRB- .
Despite the lack of conservation in this atypically located regulatory site , we demonstrated that the PhoP protein binds to the Salmonella ugd promoter in-vivo , inactivation of the PhoP box in the ugd promoter abolishes Escherichia coli is unable to promote ugd transcription under the PhoP-dependent conditions -LRB- E.A.G. , unpublished results -RRB- .
Despite the lack of conservation in this atypically located regulatory site , we demonstrated that the PhoP protein binds to the Salmonella ugd promoter in-vivo , inactivation of the PhoP box in the ugd promoter abolishes Escherichia coli is unable to promote ugd transcription under the PhoP-dependent conditions -LRB- C. Mouslim , unpublished results -RRB- .
Despite the lack of conservation in this atypically located regulatory site , we demonstrated that the PhoP protein binds to the Salmonella ugd promoter in-vivo , inactivation of the PhoP box in the ugd promoter abolishes PhoP-dependent ugd transcription is unable to promote ugd transcription under the PhoP-dependent conditions -LRB- E.A.G. , unpublished results -RRB- .
Despite the lack of conservation in this atypically located regulatory site , we demonstrated that the PhoP protein binds to the Salmonella ugd promoter in-vivo , inactivation of the PhoP box in the ugd promoter abolishes PhoP-dependent ugd transcription is unable to promote ugd transcription under the PhoP-dependent conditions -LRB- C. Mouslim , unpublished results -RRB- .