[Effect of superhelical DNA on the transcription of cloned genes of the T4 phage].
The effect of DNA superhelicity on the transcription of T4 DNA fragments containing early genes uvs W, Y and late genes 25-29 was studied. RNA polymerase transcribes both early and late phage genes within the supercoiled recombinant plasmid. Late genes relative transcription increases essentially when T4-modified RNA polymerase is used. DNA relaxation causes a sharp decrease of modified RNA polymerase activity, especially on the late genes. The same effect is obtained in intact cells with recombinant plasmid, which superhelicity is lowered by temperature-sensitive mutation in DNA gyrase. The data obtained prove that DNA superhelicity is required for the T4 late transcription by phage-modified RNA polymerase. It is suggested that the dependence of late transcription on the phage DNA replication in infected cells is connected with phage DNA superspiralization throughout its replication.
D003001:Cloning, Molecular; D004250:DNA Topoisomerases, Type II / Q000235:genetics; D004274:DNA, Recombinant; D004278:DNA, Superhelical / Q000235:genetics*; D012321:DNA-Directed RNA Polymerases / Q000235:genetics; D004926:Escherichia coli / Q000235:genetics; D005814:Genes, Viral; D009154:Mutation; D010957:Plasmids; D013604:T-Phages / Q000235:genetics*; D014158:Transcription, Genetic
D004274:DNA, Recombinant; D004278:DNA, Superhelical; D012321:DNA-Directed RNA Polymerases; D004250:DNA Topoisomerases, Type II
Vliianie sverkhspiralizatsii DNK na transkriptsiiu klonirovannykh genov faga T4.