Characterization of promoter containing DNA fragments based on the abortive initiation reaction of Escherichia coli RNA polymerase

The abortive initiation reaction of Escherichia coli RNA polymerase was demonstrated to be a general method for the rapid identification and quantitation of promoter sites on DNA. The presence of the T7 promoters, A1, A2, A3, and D on an isolated restriction fragment of the phage template was demonstrated. In addition, abortive initiation results indicated that the D promoter transcript started with pppGpUpUpG. This technique should prove particularly useful for screening DNA fragments for the number and type of promoters present.