Computational Modeling of IN-CTD/TAR Complex to Elucidate Additional Strategies to Inhibit HIV-1 Replication

HIV-1 integrase (IN) is a key enzyme that is essential for mediating the insertion of retroviral DNA into the host chromosome. IN also exhibits additional functions which are not fully elucidated, including its ability to bind to viral genomic RNA. Lack of binding of IN to RNA within the virions has been shown to be associated with production of morphologically defective virus particles. However, the exact structure of HIV-1 IN bound to RNA is not known. Based on the studies that C-terminal domain (CTD) of IN binds to TAR RNA region and based on the observation that TAR and the host factor INI1 binding to IN-CTD are identical, we computationally modelled the IN-CTD/TAR complex structure. Computational modeling of nucleic acid binding to proteins is a valuable method to understand the macromolecular interaction when experimental methods of solving the complex structures are not feasible. The current model of the IN-CTD/TAR complex may facilitate further understanding of this interaction and may lead to therapeutic targeting of IN-CTD/RNA interactions to inhibit HIV-1 replication.