title: Nucleosidediphosphate kinase in Escherichia coli: its polypeptide structure and reaction intermediate.
abstract: A nucleosidediphosphate kinase (NDP-kinase) has been highly purified from E. coli. The purified enzyme was found to have a molecular weight of approximately 64,000 daltons and be a 16,000 dalton polypeptide tetramer. The enzyme rapidly formed a phosphoenzyme when incubated with ATP in the presence of divalent cations such as Mg2+ and Ca2+ (1 mM) even at low temperatures (below 4 degrees C). The available evidence suggests that the phosphoenzyme is an enzyme-bound high energy phosphate intermediate, which functions as an intermediary in NDP-kinase action.
mesh_terms: D000596:Amino Acids / Q000032:analysis; D002413:Cations, Divalent; D004926:Escherichia coli / Q000201:enzymology*; D007700:Kinetics; D009701:Nucleoside-Diphosphate Kinase / Q000302:isolation & purification* / Q000378:metabolism; D010770:Phosphotransferases / Q000302:isolation & purification*; D013696:Temperature
chemical_list: D000596:Amino Acids; D002413:Cations, Divalent; D010770:Phosphotransferases; D009701:Nucleoside-Diphosphate Kinase