title: Characterization of fusions between the lac operon and the ilv gene cluster in Escherichia coli: ilvC-lac fusions.
abstract: By means of the general procedure of Casadaban (J. Mol. Biol. 104: 541-556, 1976), the lac genes carried on a lambda-Mu-1 hybrid phage were inserted into a temperature-inducible Mu-1 prophage that had earlier been inserted into a site near the beginning of the ilvC gene of Escherichia coli strain K-12. Selection of temperature-resistant derivatives of the lysogen resulted in a fusion of the lac genes to a region of deoxyribonucleic acid that is transcribed under the control of the ilvC regulatory elements. A strain bearing the fusion was shown to be inducible for beta-galactosidase by acetohydroxybutyrate, a natural inducer of acetohydroxy acid isomeroreductase. Induction of the lysogen by mitomycin C led to the isolation of a plaque-forming lambda derivative carrying this ilvC-lac fusion.
mesh_terms: D001431:Bacteriological Techniques; D002874:Chromosome Mapping; D002876:Chromosomes, Bacterial; D003090:Coliphages; D004926:Escherichia coli / Q000235:genetics*; D005809:Genes, Regulator; D007532:Isoleucine / Q000096:biosynthesis*; D007785:Lactose / Q000378:metabolism*; D009876:Operon; D014161:Transduction, Genetic; D014633:Valine / Q000096:biosynthesis*
chemical_list: D007532:Isoleucine; D014633:Valine; D007785:Lactose