Insight into HIV-1 reverse transcriptase-aptamer interaction from molecular dynamics simulations

Human immunodeficiency virus-1 reverse transcriptase (HIV-1 RT) is considered to be one of the key targets for antiviral drug therapy. The emergence of the aptamers as potential inhibitors against HIV-1 reverse transcriptase has attracted the attention of the scientific community because these macromolecules can effectively inhibit HIV-1 RT with between micromolar to picomolar concentrations. However, it is not clear how aptamers interact with HIV-1 RT. We have undertaken a molecular dynamics (MD) study in order to gain a keen insight into the conformational dynamics of HIV-1 RT on the formation of a complex with an aptamer or DNA substrate. We have therefore employed three separate models: apo HIV-1 RT, HIV-1 RT with a bound RNA aptamer, and HIV-1 RT with a bound DNA substrate. The results show that HIV-1 RT complex with an aptamer was more stable than that with DNA substrate. It was found that the aptamer interacted with HIV-1 RT in a fingers-and-thumb-closed conformation, at the bound at the nucleic acid substrate binding site. We identified key residues within the HIV-1 RT-aptamer complex in order to help design, develop, and test a new aptamer based on therapies in the future.