To distinguish between these alternatives , we first analyzed the expression of mgtA , pcgL , mgtC , and pmrC as an indirectly PhoP-regulated gene ( 21 , 43 ) in a phoP : : Tn10 strain , expressing PhoP from the IPTG-regu-lated plasmid pEG9014 .
The fact that mgtA was PhoP controlled led us to understand its physiological role .
The fact that mgtA was PhoP controlled led us to define the inducing signal of the regulon .
However , there is uncertainty about what consti - tutes a PhoP binding site because many PhoP-regulated pro- moters do not conform to the mgtA promoter model ( 14 , 15 ) .
For example , one of the profiles encompassed promoters that belong to the same expression ( E1 ) , PhoP box submotif ( M2 ) , and promoter class ( P1 ) ( Fig. 1H ) and harbored not only the prototypical PhoP-regulated phoP and mgtA promoters ( 13 , 14 ) but also the yhiW promoter , which was not known to be under PhoP control .
The PhoP-acti-vated mig-14 , mgtC , virK , and pagC promoters of Salmonella do not harbor a typical PhoP box in place of the 35 region , as found in archetypal PhoP-regulated promoters such as the mgtA promoter ( 13 ) .
We established that when Salmonella experiences the PhoP protein binds to both the archetypal mgtA promoter as well as the mig-14 , mgtC , and pagC promoters .
Although some genes regulated by PhoP do not display a consensus DNA recognition sequence for PhoP , other PhoP-regulated genes , such as the mgtA gene , contain a single conserved PhoP box in their promoter region ( Lejona et al. , 2003 ) .
$ , PhoP ; # , PhoP ~ P by SPR A BIAcore biosensor was used to examine , in the binding of the various PhoP proteins to the promoter of mgtA ( a PhoP-activated gene that contains a PhoP box in its promoter ) .
$ , , % , PhoPHis ~ P. Response ( RU DNA binding of PhoP proteins by SPR A BIAcore biosensor was used to examine , in the binding of the various PhoP proteins to the promoter of mgtA ( a PhoP-activated gene that contains a PhoP box in its promoter ) .
$ , , % , PhoPHis ~ P. Response ( RU DNA binding of PhoP proteins by SPR A BIAcore biosensor was used to examine , in the binding of the various PhoP proteins to the promoter of mgtA ( a PhoP-activated gene that contains a PhoP box in its promoter ) .
$ , , PhoPHis , PhoPHis ~ P. Response ( RU DNA binding of PhoP proteins by SPR A BIAcore biosensor was used to examine , in the binding of the various PhoP proteins to the promoter of mgtA ( a PhoP-activated gene that contains a PhoP box in its promoter ) .
$ , , PhoPHis , PhoPHis ~ P. Response ( RU DNA binding of PhoP proteins by SPR A BIAcore biosensor was used to examine , in the binding of the various PhoP proteins to the promoter of mgtA ( a PhoP-activated gene that contains a PhoP box in its promoter ) .
The graph shows the binding of PhoP to biotinylated oligonucleotide duplexes containing the PhoP box of the mgtA promoter .
Our SPR experiments clearly showed that both PhoP ~ P bind to the PhoP box of the mgtA promoter .
Our SPR experiments clearly showed that both PhoP bind to the PhoP box of the mgtA promoter .
Overall , this study clearly showed that the S. enterica PhoP protein binds to the mgtA promoter regardless of its phosphorylation state .
Specific binding of the various PhoP proteins to the PhoP box of the mgtA promoter .
The existence of a pair of divergently transcribed genes , Fig. 4D , is reminiscent of the mode of transcription regulation of the divergently transcribed mgtA genes of E. coli : while mgtA is activated , treR is repressed by PhoP .
The existence of a pair of divergently transcribed genes , one , is reminiscent of the mode of transcription regulation of the divergently transcribed mgtA genes of E. coli : while mgtA is activated , treR is repressed by PhoP .
The existence of a pair of divergently transcribed genes , the other , is reminiscent of the mode of transcription regulation of the divergently transcribed mgtA genes of E. coli : while mgtA is activated , treR is repressed by PhoP .
When the strain was shifted from repressing to inducing concentrations , binding of PhoP to the mgtA promoters increased during the first 10 min .
When the strain was shifted from repressing to inducing Mg2 , binding of PhoP to the mgtA promoters increased during the first 10 min .
When the strain was shifted from repressing to inducing concentrations , binding of PhoP to the mgtA promoters then asymptotically reached the steady-state levels .
When the strain was shifted from repressing to inducing Mg2 , binding of PhoP to the mgtA promoters then asymptotically reached the steady-state levels .
This motif in such promoters depends functionally on its orientation , probably because the reverse sequence in this box would change the interaction of PhoP and RNA polymerase , thereby nullifying PhoP-regulated mgtA transcription ( unpublished data ) .
To further investigate the association between tdcA with phoP , we constructed chromosomal lacZ fusion strains of PhoP-regulated ( mgtA and pagD ) and SPI2 genes ( ssaG and sseA ) ( Navarre et al. , 2005 ) .
In both strains , transcription initiation from the mgtA promoter is controlled by the transcription factor PhoP in response to extracytoplasmic Mg2 .
By contrast , the MgtA-mediated feedback takes place relatively late as it requires cytosolic Mg2 + levels to drop below a certain threshold ( Fig. 2A ) , and does not appear to be related to virulence because neither mgtA nor the PhoP-regulated genes whose expression is most affected upon mgtA deletion are necessary for Salmonella to cause a lethal infection in mice ( Gunn et al. , 1998 ; Gunn et al. , 1995 ; Blanc-Potard and Groisman , 1997 ) .
By contrast , the MgtA-mediated feedback takes place relatively late as it requires cytosolic Mg2 + levels to drop below a certain threshold ( Fig. 2A ) , and does not appear to be related to virulence because neither mgtA nor the PhoP-regulated genes whose expression is most affected upon mgtA deletion are necessary for Salmonella to cause a lethal infection in mice ( Gunn et al. , 1998 ; Gunn et al. , 1995 ; Blanc-Potard and Groisman , 1997 ) .
To identify the PhoP-regulated gene ( s ) responsible for motility on 0.3 % agarose low Mg2 + media , we tested the behavior of strains mutated in each of 19 different PhoP-activated genes ( mgtA , mgtB , mgtC , mig-14 , pagC , pagK , pagM , pagN , pagO , pagP , pcgL , pgtE , phoN , pmrD , rstA , slyA , ugtL , virK , and yobG ) .
To determine whether acetylation affects the activity of PhoP as a transcription factor , several known PhoP-regulated genes including mgtA , mgtC , pmrA and pagC were selected to evaluate the role of Pat in the regulation of PhoP activity .
To determine whether acetylation affects the activity of PhoP as a transcription factor , mgtA were selected to evaluate the role of Pat in the regulation of PhoP activity .