Structural basis for the resilience of efavirenz (DMP-266) to drug resistance mutations in HIV-1 reverse transcriptase.
Ren, J., Milton, J., Weaver, K.L., Short, S.A., Stuart, D.I., Stammers, D.K.(2000) Structure 8: 1089-1094
- PubMed: 11080630 
- DOI: https://doi.org/10.1016/s0969-2126(00)00513-x
- Primary Citation of Related Structures:  
1FK9, 1FKO, 1FKP - PubMed Abstract: 
Efavirenz is a second-generation non-nucleoside inhibitor of HIV-1 reverse transcriptase (RT) that has recently been approved for use against HIV-1 infection. Compared with first-generation drugs such as nevirapine, efavirenz shows greater resilience to drug resistance mutations within HIV-1 RT. In order to understand the basis for this resilience at the molecular level and to help the design of further-improved anti-AIDS drugs, we have determined crystal structures of efavirenz and nevirapine with wild-type RT and the clinically important K103N mutant. The relatively compact efavirenz molecule binds, as expected, within the non-nucleoside inhibitor binding pocket of RT. There are significant rearrangements of the drug binding site within the mutant RT compared with the wild-type enzyme. These changes, which lead to the repositioning of the inhibitor, are not seen in the interaction with the first-generation drug nevirapine. The repositioning of efavirenz within the drug binding pocket of the mutant RT, together with conformational rearrangements in the protein, could represent a general mechanism whereby certain second-generation non-nucleoside inhibitors are able to reduce the effect of drug-resistance mutations on binding potency.
Organizational Affiliation: 
Structural Biology Division The Wellcome Trust Centre for Human Genetics University of Oxford OX3 7BN, Oxford, United Kingdom.