title: pyrR identical to pyrH in Salmonella typhimurium: control of expression of the pyr genes.
abstract: Mutants of Salmonella typhimurium showing constitutive synthesis of the pyrimidine biosynthetic enzymes coded for by the pyrA-F genes (G. A. O'Donavan and J. C. Gerhart, 1972) have been reinvestigated. The high rate of expression of the pyrB-F genes in these mutants as well as their pyrimidine excretion is shown to be due to mutations in the gene pyrH encoding uridine 5'-monophosphate kinase. Thus, the term pyrR used for these mutants should be replaced by the designation pyrH.
mesh_terms: D001221:Aspartate Carbamoyltransferase / Q000096:biosynthesis; D004794:Enzyme Repression; D005796:Genes; D005809:Genes, Regulator; D009154:Mutation; D010770:Phosphotransferases / Q000096:biosynthesis*; D011743:Pyrimidines / Q000096:biosynthesis*; D012486:Salmonella typhimurium / Q000187:drug effects / Q000201:enzymology*; D014529:Uridine / Q000031:analogs & derivatives / Q000494:pharmacology; D014541:Uridine Kinase / Q000096:biosynthesis*
chemical_list: D011743:Pyrimidines; D001221:Aspartate Carbamoyltransferase; D010770:Phosphotransferases; D014541:Uridine Kinase; D014529:Uridine