title: Rapid turnover of mannitol-1-phosphate in Escherichia coli.
abstract: The phosphate moiety of D-mannitol-1-phosphate in Escherichia coli is subject to rapid turnover and is in close equilibrium with Pi and the phosphorus of fructose-1,6-bisphosphate. These three compounds account for the bulk of 32P label found in cells after several minutes of uptake of 32Pi and mannitol-1-phosphate represents some 30% of this label. Mannitol-1-phosphate occurs in E. coli grown on a variety of carbon sources, in the absence of D-mannitol, and is synthesized de novo even in mutants lacking mannitol-1-phosphate dehydrogenase. The mannitol moiety of mannitol-1-phosphate was not affected during the total chase of the P moiety, which exchanged with a half-life of about 30 s. These findings suggest that the rapid equilibration of the phosphorus is a function of an enzyme, possibly a component of the phosphotransferase system, capable of forming a complex that allows the exchange of the phosphate without the equilibration of the mannitol moiety with free mannitol.
mesh_terms: D004926:Escherichia coli / Q000201:enzymology / Q000235:genetics / Q000378:metabolism*; D029968:Escherichia coli Proteins; D005635:Fructosediphosphates / Q000378:metabolism; D007700:Kinetics; D008353:Mannitol / Q000378:metabolism; D008355:Mannitol Phosphates / Q000378:metabolism*; D009004:Monosaccharide Transport Proteins; D009154:Mutation; D010710:Phosphates / Q000378:metabolism; D010731:Phosphoenolpyruvate Sugar Phosphotransferase System / Q000235:genetics / Q000378:metabolism; D013401:Sugar Alcohol Dehydrogenases / Q000235:genetics / Q000378:metabolism; D013403:Sugar Phosphates / Q000378:metabolism*
chemical_list: D029968:Escherichia coli Proteins; D005635:Fructosediphosphates; D008355:Mannitol Phosphates; D009004:Monosaccharide Transport Proteins; D010710:Phosphates; D013403:Sugar Phosphates; C030070:mannitol-1-phosphate; D008353:Mannitol; D013401:Sugar Alcohol Dehydrogenases; C021544:mannitol-1-phosphate dehydrogenase; D010731:Phosphoenolpyruvate Sugar Phosphotransferase System; C022358:mannitol PTS permease, E coli; C029063:fructose-1,6-diphosphate