THE BACTERIAL PHOSPHOTRANSFERASE SYSTEM - NEW FRONTIERS 30 YEARS LATER

In 1964, Kundig, Ghosh and Roseman reported the discovery of the phosp hoenolpyruvate:sugar phosphotransferase system (PTS). Thirty years lat er, we find that the PTS functions not only as a sugar-phosphorylating system, but also as a complex protein kinase system that regulates a wide variety of metabolic processes and controls the expression of num erous genes. As a result of recent operon- and genome-sequencing proje cts, novel PTS protein-encoding genes have been discovered, most of wh ich have yet to be functionally defined. Some of them appear to be inv olved in cellular processes distinct from those recognized previously. Fundamental aspects of past and current PTS research are briefly revi ewed, and recent advances are integrated into conceptual pictures that provide guides for future research.