title: The location of purine phosphoribosyltransferase activities in Escherichia coli.
abstract: During the preparation of spheroplasts, adenine phosphoribosyltransferase (EC 2.4.2.7) and hypoxanthine phosphoribosyltransferase (EC 2.4.2.8) were released in parallel with cytidine deaminase (EC 3.5.4.5) and uridine phosphorylase (EC 2.4.2.3), which, on other evidence, are considered to be located intracellularly. The two phosphoribosyltransferases and uridine phosphorylase were not significantly associated with purified membrane fractions as was purine nucleoside phosphorylase (EC 2.4.2.1). The effects of the poorly permeable enzyme-inactivating reagents, 4-diazoniumbenzenesulphonate, 7-diazonium-1,3-naphthalene-disulphonate and 2,4,6-trinitrobenzenesulphonate, on Escherichia coli indicate that all the above-mentioned enzymes and also the xanthine-guanine phosphoribosyltransferase [Miller, Ramsey, Krenitsky & Elion (1972) Biochemistry 11, 4723--4731] are located intracellularly.
mesh_terms: D000228:Adenine Phosphoribosyltransferase / Q000378:metabolism*; D003979:Diazonium Compounds / Q000494:pharmacology; D004926:Escherichia coli / Q000201:enzymology*; D007041:Hypoxanthine Phosphoribosyltransferase / Q000378:metabolism*; D007425:Intracellular Membranes / Q000201:enzymology; D009997:Osmotic Pressure; D010430:Pentosyltransferases / Q000378:metabolism*; D013104:Spheroplasts / Q000378:metabolism; D014302:Trinitrobenzenesulfonic Acid / Q000494:pharmacology
chemical_list: D003979:Diazonium Compounds; D014302:Trinitrobenzenesulfonic Acid; D010430:Pentosyltransferases; D000228:Adenine Phosphoribosyltransferase; D007041:Hypoxanthine Phosphoribosyltransferase