Specifically , RtsA binds to the hilA regulatory gene promoter in SPI-1 while RtsB binds to the flhDC regulatory operon promoter in the flagellar regulon .
RtsB have also been shown to regulate SPI-1 genes and flhDC , respectively .
However , unlike HilD , RtsB is a negative regulator of flhDC .
RtsB also regulate cell motility by interacting with the flhDC promoter .