title: Interaction of the operator of the tryptophan operon with repressor.
abstract: Transcription studies in vitro on repression of the tryptophan operon of Escherichia coli show that partially purified trp repressor binds specifically to DNA containing the trp operator with a repressor-operator dissociation constant of about 0.2 nM in 0.12 M salt at 37 degrees , a value consistent with the extent of trp operon regulation in vivo. The half-life of the trp repressor-trp operator complex is less than 2 min in vitro in 0.12 M salt.
mesh_terms: D003090:Coliphages / Q000378:metabolism; D004267:DNA Viruses / Q000378:metabolism; D012321:DNA-Directed RNA Polymerases / Q000378:metabolism; D004794:Enzyme Repression; D005809:Genes, Regulator; D006207:Half-Life; D009693:Nucleic Acid Hybridization; D009876:Operon; D013698:Templates, Genetic; D014158:Transcription, Genetic; D014316:Tritium; D014364:Tryptophan / Q000378:metabolism*
chemical_list: D014316:Tritium; D014364:Tryptophan; D012321:DNA-Directed RNA Polymerases