title: Mutation that affects pepN translation initiation in Escherichia coli.
abstract: Mutants altered in their expression of the hybrid pepN-lacZ gene have been selected for resistance to p-nitrophenyl-beta-D-thiogalactopyranoside (a bacteriostatic compound that enters the cells via lac permease). A unique mutation decreasing the level of pepN expression to 9% of that of the wild type has been studied in detail. This mutation controls in cis the expression of the pepN gene. The pepN region from a pepN-lacZ gene fusion has been cloned and sequenced. Comparison of the mutant and wild type sequences indicates that the mutation lies between the Shine-Dalgarno sequence (AGGT) and the initiation codon (AUG). This mutation is a T----C transition which might allow the formation of a stable secondary structure in the region of translation initiation thus decreasing the level of pepN expression.
mesh_terms: D000626:Aminopeptidases / Q000235:genetics*; D010582:Bacteriophage lambda / Q000235:genetics; D001483:Base Sequence; D018826:CD13 Antigens; D003001:Cloning, Molecular; D003062:Codon; D004269:DNA, Bacterial / Q000235:genetics; D004274:DNA, Recombinant; D004352:Drug Resistance, Microbial / Q000235:genetics; D004926:Escherichia coli / Q000235:genetics*; D005798:Genes, Bacterial; D009154:Mutation; D009690:Nucleic Acid Conformation; D010442:Peptide Chain Initiation, Translational; D013862:Thiogalactosides
chemical_list: D003062:Codon; D004269:DNA, Bacterial; D004274:DNA, Recombinant; D013862:Thiogalactosides; C010256:o-nitrophenol beta-thiogalactoside; D000626:Aminopeptidases; D018826:CD13 Antigens