The bacterial phosphotransferase system: kinetic characterization of the glucose, mannitol, glucitol, and N-acetylglucosamine systems.
The kinetic mechanisms by which the glucose, glucitol, N-acetylglucosamine, and mannitol enzymes II catalyze sugar phosphorylation have been investigated in vitro. Lineweaver-Burk analyses indicate that the glucose and glucitol enzymes II catalyze sugar phosphorylation by a sequential mechanism when the two substrates are phospho-enzyme III and sugar. The N-acetylglucosamine and mannitol enzymes II, which do not function with an enzyme III, catalyze sugar phosphorylation by a ping-pong mechanism when the two substrates are phospho-HPr and sugar. These results, as well as previously published kinetic characterizations, suggest a common kinetic mechanism for all enzymes II of the system. It is suggested that all enzymes II and enzyme II-III pairs arose from a single (fused) gene product containing two sites of phosphorylation and that phosphoryl transfer from the second phosphorylation site to sugar can only occur when the enzyme II-III pair is present in the associated state.
D000117:Acetylglucosamine / Q000378:metabolism*; D004926:Escherichia coli / Q000201:enzymology*; D029968:Escherichia coli Proteins; D005944:Glucosamine / Q000031:analogs & derivatives*; D005947:Glucose / Q000378:metabolism; D007700:Kinetics; D008757:Methylglucosides / Q000378:metabolism; D009004:Monosaccharide Transport Proteins; D010731:Phosphoenolpyruvate Sugar Phosphotransferase System / Q000378:metabolism; D010766:Phosphorylation; D010770:Phosphotransferases / Q000378:metabolism*; D012486:Salmonella typhimurium / Q000201:enzymology*; D013012:Sorbitol / Q000378:metabolism; D013379:Substrate Specificity
D029968:Escherichia coli Proteins; D008757:Methylglucosides; D009004:Monosaccharide Transport Proteins; D013012:Sorbitol; C027020:methylglucoside; D010770:Phosphotransferases; D010731:Phosphoenolpyruvate Sugar Phosphotransferase System; C022358:mannitol PTS permease, E coli; D005947:Glucose; D005944:Glucosamine; D000117:Acetylglucosamine