Figure 3.

Signaling in the VanS-VanR phosphorelays and activation of the type A and B VRE promoters. Sensor kinase reaction scheme involves its autophosphorylation and phosphotransfer to the response regulator (thick solid arrows) leading to activation of the respective promoters (thick dashed arrow). Phosphatase reaction of the sensor kinase dephosphorylates the cognate response leading to down-regulation of the promoter in the absence of external stimulus (thin dashed arrows). While VanS_a has both kinase and phosphatase activities, whether VanS_b has a kinase activity has not been established (see text).