Uncovering the Complexities of Retroviral Ribonuclease H Reveals its Potential as a Therapeutic Target
George J. Klarmann 1, Mary E. Hawkins 1, Stuart F.J. Le Grice 1
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*Correspondence: George J. Klarmann, Email not available
Abstract
Successful long-term management of HIV infection will require targeted inhibition of multiple steps essential for virus replication. Currently, both nucleoside- and nonnucleoside-based inhibitors of DNA polymerase function, in combination with antagonists of HIV protease, have been shown to be clinically beneficial. However, it is clear that RNase H activity of the multifunctional HIV-1 reverse transcriptase (RT) is absolutely required for completion of retroviral DNA synthesis, thereby rendering this function an attractive target for drug development. Although generally viewed as a sequence-independent activity, highly precise RNase H cleavage is required in order to remove the RNA primers of (-) and (+) strand DNA synthesis (a host-derived tRNA and the polypurine tract, respectively), thereby preserving the ends of linear DNA and facilitating integration. The availability of highly purified, recombinant RT/RNase H has allowed a thorough dissection of these multiple events and their potential for therapeutic intervention. Our current understanding of retroviral RNase H function and the status of small molecule inhibitors are the focus of this review.
