title: Release of polarity in Escherichia coli by gene N of phage lambda: termination and antitermination of transcription.
abstract: The induction of lambda prophage provokes the constitutive expression of the adjacent gal operon in E. coli. This "escape synthesis" can result from transcription that initiates at a phage promoter and extends into the gal operon. The effect requires the product of the lambda gene N. N-mediated transcription not only fails to terminate at the prophage-bacterial junction and at the ends of bacterial operons, but ignores termination signals caused by polar insertions or ochre mutations within gal. Suppression of polarity by N-function is a cis-effect; only transcription initiated at the phage promoter is influenced. We propose that the transcription complex is influenced by N-product to become termination-resistant at a site in the phage genome (juggernaut model). This site appears to be at or near the phage promoter.
mesh_terms: D002874:Chromosome Mapping; D002876:Chromosomes, Bacterial; D003090:Coliphages / Q000378:metabolism*; D004267:DNA Viruses / Q000378:metabolism; D004926:Escherichia coli / Q000378:metabolism*; D005690:Galactose / Q000378:metabolism*; D005809:Genes, Regulator; D008242:Lysogeny; D009154:Mutation; D009876:Operon; D014158:Transcription, Genetic
chemical_list: D005690:Galactose