Bacterial nitrogen-related phosphotransferase systems: new insights into diverse roles in virulence, physiology, and central metabolism

ABSTRACT Nitrogen-related phosphotransferase (PTS Ntr ) systems are highly conserved and widely distributed in proteobacteria. These systems are thought to enable bacteria to sense and respond to changes in cellular carbon and nitrogen availability. The PTS Ntr is analogous to the carbohydrate phosphotransferase systems that carry out phosphorylation and uptake of specific carbohydrates. Instead of targeting carbohydrates, the PTS Ntr influences metabolic flux, virulence, biofilm development, stress adaptation, and other phenotypes in ways that vary among different species. Mechanistic insights into the regulatory roles of the PTS Ntr have emerged from studies in diverse bacteria, including Escherichia coli , agriculturally relevant nitrogen-fixing symbionts, and biotechnology-relevant and opportunistic pathogens of the Pseudomonas genus. In this review, we summarize both seminal and more recent discoveries underpinning the current understanding of PTS Ntr and identify unifying themes that connect these systems across disparate species.