title: Mutant strains of Salmonella typhimurium with defective phosphoribosylpyrophosphate synthetase activity.
abstract: A mutant of Salmonella typhimurium with undetectable phosphoribosylpyrophosphate (PRPP) synthetase activity in vitro and abnormally low PRPP pools in vivo was identified by screening temperature-sensitive isolates by an autoradiographic procedure. The lack of PRPP synthetase activity in vitro and temperature-sensitive growth were shown to result from separate, but closely linked mutations mapping at 47 units on the Salmonella chromosome. Mutant cell extracts prepared by a variety of methods did not show any detectable PRPP synthetase activity, but material that was immunochemically cross-reactive with PRPP synthetase was detected by complement fixation analysis. A second mutant, isolated by localized mutagenesis, contained about half the PRPP synthetase and cross-reacting material of the parental strain.
mesh_terms: D000906:Antibodies / Q000276:immunology; D002874:Chromosome Mapping; D002876:Chromosomes, Bacterial; D003168:Complement Fixation Tests; D003429:Cross Reactions; D006358:Hot Temperature; D009154:Mutation; D010770:Phosphotransferases / Q000378:metabolism*; D012268:Ribose-Phosphate Pyrophosphokinase / Q000276:immunology / Q000378:metabolism*; D012486:Salmonella typhimurium / Q000201:enzymology / Q000235:genetics*
chemical_list: D000906:Antibodies; D010770:Phosphotransferases; D012268:Ribose-Phosphate Pyrophosphokinase