The activity of Escherichia coli DNA-dependent RNA polymerase on DNA templates of different origin. The effect of cAMP.

DNA isolated from different T phages served as a better template for the synthetic activity of unmodified Escherichia coli RNA polymerase in the in vitro system than did the host DNA. cAMP significantly stimulated the activity of such a preparation of RNA polymerase. The stimulation was more pronounced with the host DNA template than with phage DNA. However, the synthetic activity of Escherichia coli RNA polymerase was greater in the presence of cAMP than without it when phage DNA served as the template.