Regulatory roles of the bacterial nitrogen-related phosphotransferase system

In addition to the sugar phosphotransferase system (sugar PTS) dedicated to carbohydrate uptake, many Gram-negative bacteria possess a so-called nitrogen PTS (PTS(Ntr)). Although fulfilling very different functions, both systems can communicate with each other by phosphate exchange. PTS(Ntr) regulates diverse processes implicated in metabolism of nitrogen and carbon, and is essential for virulence in some bacteria. Additionally, it plays a role in potassium homeostasis by regulating the expression and activity of a high- and a low-affinity K(+) transporter, respectively. In this article, we review recent advances in the understanding of the regulatory roles of PTS(Ntr) in various organisms.