Mechanistic model for HITME recombination by a second tRNA priming event during minus-strand DNA synthesis

<p><b>Copyright information:</b></p><p>Taken from "Hairpin-induced tRNA-mediated (HITME) recombination in HIV-1"</p><p>Nucleic Acids Research 2006;34(8):2206-2218.</p><p>Published online 2 May 2006</p><p>PMCID:PMC1456326.</p><p>© The Author 2006. Published by Oxford University Press. All rights reserved</p> Reverse transcription is initiated by the tRNA primer that is annealed to the PBS. Strong-stop minus-strand DNA (ss-DNA) is synthesized by RT by copying the 5′ R region. The ss-DNA is translocated to the homologous 3′ R sequence (first strand transfer), and reverse transcription continues. The extended lhNef hairpin will cause pausing of the RT enzyme. A spurious tRNA acts as a second primer for minus-strand DNA synthesis. The ppt primes the synthesis of strong-stop plus-strand DNA (ss+DNA), which is translocated to the 5′ end of the minus-strand cDNA (second strand transfer). The minus-strand cDNA and the 2nd tRNA primer are copied during continued plus-strand DNA synthesis. Sequence complementarity between plus-strand copy of the 2nd tRNA primer and the minus-strand DNA facilitates a third strand transfer that is needed to complete reverse transcription. The non-natural priming and strand transfer events result in insertion of the tRNA sequence into the viral genome and deletion of the lhNef sequence. The tRNA sequence is in red and complementary nucleotides between tRNA and HIV-lhNef are boxed in blue