Structure of HIV-1 RT/TIBO R 86183 complex reveals similarity in the binding of diverse nonnucleoside inhibitors

We report the structure of HIV-1 Reverse Transcriptase (RT) complexed with the nonnucleoside inhibitor TIBO R 86183 at 3.0 A resolution. Comparing this structure with those of complexes of HIV-1 RT/alpha-APA R 95845 and HIV-1 RT/nevirapine provides a basis for understanding the nature of nonnucleoside inhibitor binding, the structure of the binding site and the interactions between the bound inhibitors and surrounding amino acid residues as well as for understanding mechanisms of inhibition by and resistance to nonnucleoside inhibitors. All three inhibitors considered assume a similar butterfly-like shape and bind to HIV-1 RT in a very similar way. Important differences occur in the conformation of amino acid residues that form the binding pocket.