title: Isolation and characterization of mutations in the structural gene for protease III (ptr).
abstract: Escherichia coli mutants defective in protease III were isolated by enzyme assays of heavily mutagenized colones. One mutant produced thermolabile enzyme, and it is presumed to have a mutation in the structural gene of protease III. Two other mutants mapping at the same site had less than 5% of the wild-type protease III level. The genetic locus of these mutations, designated ptr, was located at approximately 60 min on the E. coli linkage map based on its high frequency (70%) of contransduction by P1 with argA. Strains with less than 5% of the wild-type protease III activity grew normally and degraded nonsense fragments of beta-galactosidase at wild-type rates.
mesh_terms: D002874:Chromosome Mapping; D002876:Chromosomes, Bacterial; D004926:Escherichia coli / Q000201:enzymology / Q000235:genetics*; D005796:Genes; D009154:Mutation; D010447:Peptide Hydrolases / Q000235:genetics* / Q000378:metabolism
chemical_list: D010447:Peptide Hydrolases