Besides the mgtA gene , only 2 of these 13 overlapping operons were directly regulated by the PhoPQ two-component system organisms .
Besides the mgtA gene , only 2 of these 13 overlapping operons were directly regulated by the PhoPQ two-component system in .
Superimposed on the regulation of transcription initiation by the PhoPQ system , the mgtA gene is subject to an additional control mechanism .
The result that the expression of the mgtA-lacZ fusion is essentially insensitive to the Mg2 concentration in the ribos-witch mutants is unexpected , because the initiation of transcription at the mgtA promoter would be predicted to be subject to residual control by this cation via the PhoPQ system .