DETAILED MODEL OF REVERSE TRANSCRIPTION AND TESTS OF CRUCIAL ASPECTS

A model of reverse transcription has been devised by which the detailed architecture of ten molecular structures is predicted. The model includes a number of novel features for which experimental evidence is presented. First, growing minus DNA strand is copied from the viral RNA only up to a position about 150 nucleotides from the 5′ end of the RNA. Second, plus-strand DNA, after being copied from approximately 600 nucleotides at the 5′ end of the minus-strand DNA, then transcribes the first approximately 20 nucleotides of the tRNApro primer (which is covalently attached to the 5′ end of the minus DNA strand). The 3′ ends of the minus and plus DNA probably form a hybrid through the homology conferred by the primer binding site sequences. Third, the minus and plus DNA strands are elongated in a continuous fashion resulting in a linear double-stranded DNA molecule containing a 600 nucleotide direct repeat at both ends. Thus most of the features of the model have experimental support, and it appears to provide a credible description of reverse transcription. © 1979.