In Salmonella , SirA also directly activates the horizontally acquired regulatory genes hilC .
In contrast , the presence of a hilD mutation completely blocked SirA induction of hilC .
Our data suggest that SirA induces expression of hilC via HilD .
In support of our model , we demonstrate that SirA induction of hilC requires the presence of HilD .
SirA does this by directly activating hilC regulatory genes .
SirA controls these genes by directly activating hilC regulatory genes .
On the basis of these data , the authors concluded that SirA activates the system by direct action on hilC .
SirA , positively regulates hilC .
SirA positively controls the transcription of hilC .
SirA , positively regulates the transcription of hilC .