Inhibition of reverse transcription of 70S and 35S avian myeloblastosis RNAs by nonprimer tRNA's.

We studied the kinetics of the reverse transcription of 70S and 35S RNA of avian myeloblastosis virus in the presence and absence of various tRNA's. All tRNA's inhibited synthesis. tRNA's from Escherichia coli and yeast exhibited a noncompetitive type of inhibition, i.e., they bound reversibly and randomly and did not alter the affinity of the viral RNA for the polymerase. Nonprimer tRNA's obtained from 70S RNA molecules produced a complex pattern of inhibition. The results show that the nonprimer tRNA's which bound to the reverse transcriptase decreased the affinity of the viral RNA for the enzyme. The maximum rate of synthesis with 70S RNA as the template was less than that with 35S RNA, presumably because the former contains nonprimer tRNA's which can interact with the polymerase.