Site-directed transcription initiation with a mobile promoter

A method is described for the high-level transcription of any DNA segment using bacteriophage RNA polymerases (RNAPs). A synthetic mobile promoter with a template-complementary 3' extension is ligated to the target sequence of interest. Transcription with an appropriate RNAP results in an amplification of approx. 70-fold. In the presence of heterologous DNA, bacteriophage RNAPs are shown to be specific for their cognate mobile promoters.