The Starting Nucleotide Sequences and Size of RNA Transcribed in vitro on Phage DNA Templates

Excerpt

With the discovery of transcriptional factors acting during initiation and termination of RNA synthesis (Burgess et al., 1969; Krakow et al., 1969; Roberts, 1969), a number of studies were designed to gain further insight into the molecular mechanism of the selective transcription of genes. Our approach was to characterize RNA chains transcribed in vitro on phage DNA templates and to investigate the conditions permitting specific initiation and termination of such RNA chains. RNA synthesis in vitro is known to be initiated with the incorporation of an intact ATP or GTP to form the 5′-terminus of the chain (Maitra and Hurwitz, 1965; Bremer et al., 1965). By using γ-³²P-GTP or γ-³²P-ATP of high specific activity, it is possible to label the starting sequences of the RNA synthesized. Applying this terminal labeling method, we analyzed the starting sequences and size of RNA transcribed by E. coli RNA polymerase on two phage DNA...