PMID:4867974

Citation	Ippen, K, Miller, JH, Scaife, J and Beckwith, J (1968) New controlling element in the Lac operon of E. coli.Nature 217:825-7
Abstract	No abstract in PubMed
Links	PubMed
Keywords	Chromosome Mapping; Escherichia coli; Genes, Regulator; Genetic Code; Genetics, Microbial; Mutation; Recombination, Genetic
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Main Points of the Paper

• Genetic site altered in the promoter mutants unambiguously maps between i and o
  • this is a new controlling element determining the expression of the lac operon

• Mutations are cis dominant
  • only reduce the rate of expression of the operon in the same chromosome
  • these effects are not relieved by the introduction of a second lac region into the cell

Materials and Methods Used

• UV mutagenesis to generate mutants

Phenotype Annotations

Species	Taxon ID	Strain	Gene (if known)	OMP	Phenotype	Details	Evidence	Notes
Escherichia coli	NCBI:562	L29		Decreased rate of lac operon expression?	Growth	reduced rate of lac operon expression (4% of wild type expression) Cis-dominant		Table 1-identifying the promoter region
Escherichia coli	NCBI:562	L1		Decreased rate of lac operon expression?	Growth	reduced rate of lac operon expression (2% of wild type expression) Cis-dominant		Table 1
Escherichia coli	NCBI:562	L1		Partially constitutive expression of the lac operon Decreased repressor activity of LacI	Growth	Partially constitutive Reduced activity of i gene		Table 1
Escherichia coli	NCBI:562	L8		Decreased rate of lac operon expression?	Growth	reduced rate of lac operon expression (6% of wild type expression) Cis-dominant		Table 1
Escherichia coli	NCBI:562	L37		Cis-dominant	Growth	reduced rate of lac operon expression (6% of wild type expression)		Table 1
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