title: Identification of bacteriophage T4D gene 29 product, a baseplate hub component, as a folylpolyglutamate synthetase.
abstract: An assay for folylpolyglutamate synthetase activity in extracts of uninfected and bacteriophage T4D-infected Escherichia coli B has been developed. T4D infection induced the formation of a new synthetase raising the total synthetase activity three-fold. Extracts obtained after infection with T4 gene 51, 27 or 28 amber mutants showed increased synthetase activities while extracts obtained from cells infected with a T4D gene 29 amber mutant did not show any increase in synthetase activity. The phage-induced synthetase was found to copurify with the gene 29 product and a 100-fold purified synthetase of molecular size of 74,000 daltons has been obtained. The purified synthetase has a folate substrate specificity different from the host synthetase since it added glutamate residues to dihydrofolate as well as to the usual tetrahydrofolate substrate.
mesh_terms: D002268:Carboxypeptidases / Q000235:genetics*; D004926:Escherichia coli / Q000201:enzymology / Q000235:genetics*; D005796:Genes; D005814:Genes, Viral; D005816:Genetic Complementation Test; D007700:Kinetics; D009154:Mutation; D013379:Substrate Specificity; D013604:T-Phages / Q000201:enzymology / Q000235:genetics*; D014764:Viral Proteins / Q000235:genetics* / Q000302:isolation & purification; D011623:gamma-Glutamyl Hydrolase / Q000235:genetics* / Q000378:metabolism
chemical_list: D014764:Viral Proteins; D002268:Carboxypeptidases; D011623:gamma-Glutamyl Hydrolase