Mutational analysis of HIV-1 long terminal repeats to explore the relative contribution of reverse transcriptase and RNA polymerase II to viral mutagenesis.

摘要: HIV-1 evolves rapidly, which is thought to result from one or more error-prone steps in the virus life cycle. Because reverse transcriptase (RT) does not possess 3'- 5'-exonucleolytic proofreading activity and because RT has been shown be cell free systems, it should an important contributor high rate of mutation. However, RNA polymerase II (pol II) synthesizes viral RNA, might also contribute significantly mutagenesis. To assess relative contributions pol mutagenesis, a system was established study nature mutations long terminal repeats (LTRs). Owing unique replication at ends genome, mutational analysis retroviral LTRs provides opportunity evaluate contribution Mutational performed on both 215 proviruses, restricted single cycle replication, employing single-stranded conformational polymorphism DNA sequencing allowing direct identification absence selection within autologous sequences. A total 21 independent identified. Ten were observed LTRs, could have introduced by either II, whereas other eleven only present LTR RT. This first evidence that contributes mutagenesis likely primary engine for Moreover, U3-R border, but their frequency differed experiments using cell-free systems suggesting and/or cellular factors fidelity genome.