In vitro transcription of theavian oncornavirus genome by the RNA-directed DNA polymerase: analysis of DNA transcripts synthesized in reconstructed enzymatic reactions.

We have analyzed the DNA products synthesized in vitro in reconstructed reactions containing purified avian oncornavirus genome RNA and RNA-directed DNA polymerase. The results of these studies indicate that: (i) the initial DNA product synthesized on either 70S RNA or reconstituted 35S RNA-tRNAtrp template - primer complexes in the presence of low concentrations of deoxynucleoside triphosphates consists of several discrete size classes, none of which exceed 200 nucleotides in length; (ii) large DNA transcripts (about 2,000 nucleotides) can be synthesized on both 70S RNA and the 35S RNA - tRNAtrp complex by increasing the deoxynucleoside triphosphate concentration; and (iii) DNA synthesized by detergent-disrupted virus is considerably longer than DNA synthesized in reconstructed reactions.