title: Pyruvate-uridine diphospho-N-acetylglucosamine transferase. Purification to homogeneity and feedback inhibition.
abstract: Phosphoenolpyruvate:uridine-5'-diphospho-N-acetyl-2-amino-2-deoxyglucose-3-enolpyruvyltranferase catalyzes the transfer of enolpyruvate from phosphoenolpyruvate to uridine diphospho-N-acetylglucosamine with the liberation of inorganic orthophosphate. It was purified to homogeneity from Enterobacter cloacae with the use of UDP-N-acetylmuramyl-L-Ala-D-Glu-meso-Dap, a feedback inihibitor, as a ligand covalenty bound to Sepharose 4B. The evidence suggests that the enzyme is a single polypeptide with a molecular weight of 41,000. The enzyme catalyzes the first committed step in the biosynthesis of bacterial cell wall peptidoglycan. The cytoplasmic end product of this pathway is UDP-N-acetylmuramyl-L-Ala-D-Glu-meso-Dap-D-Ala-D-Ala (see article). UDP-MurNAc-pentapeptide and its precursor, UDP-MurNAc-tripeptide, were found to be effective inhibitiors of the enzyme. The kinetic data suggest a binding site for these inhibitors distinct from the active site. This is consistent with the proposed role for UDP-MurNAc-tripeptide and pentapeptide as negative modulators of the enzyme.
mesh_terms: D000595:Amino Acid Sequence; D000596:Amino Acids / Q000032:analysis; D002846:Chromatography, Affinity; D002852:Chromatography, Ion Exchange; D004229:Dithiothreitol / Q000494:pharmacology; D004591:Electrophoresis, Polyacrylamide Gel; D004755:Enterobacteriaceae / Q000201:enzymology; D005944:Glucosamine; D006146:Guanidines / Q000494:pharmacology; D007700:Kinetics; D008433:Mathematics; D008970:Molecular Weight; D010728:Phosphoenolpyruvate; D014166:Transferases / Q000037:antagonists & inhibitors / Q000302:isolation & purification*; D014539:Uridine Diphosphate Sugars
chemical_list: D000596:Amino Acids; D006146:Guanidines; D014539:Uridine Diphosphate Sugars; D010728:Phosphoenolpyruvate; D014166:Transferases; D005944:Glucosamine; D004229:Dithiothreitol