Figure 4.
Priming sites for reverse transcription. LTR sequences are underlined and square brackets denote the LTR boundaries. (A) The primer binding site (PBS) is complementary to the 3′ end of the ASP tRNA. Complementary sequences are shaded, including those that form G:U base pairs. (B) Polypurine tracts following the envelope(env)-like ORF (PPT1) and near the 3′ LTR (PPT) are characterized by the shaded, conserved core motif.
