Introduction: Protein phosphorylation and signal transduction in bacteria

AbstractA single type of reversible protein‐phosphorylating system, the ATP‐dependent protein kinase/phosphatase system, is employed in signal transduction in eukaryotes. By contrast, recent work has revealed that three types of protein‐phosphorylating systems mediate signal transduction in bacteria. These systems are (1) classical protein kinase/phosphatase systems, (2) sensor‐kinase/response‐regulator systems, and (3) the multifaceted phosphoenolpyruvate‐dependent phosphotransferase system. Physiological, structural, and mechanistic aspects of these three evolutionarily distinct systems are discussed in the papers of this written symposium. © 1993 Wiley‐Liss, Inc.