Complexes of HIV-1 reverse transcriptase with inhibitors of the HEPT series reveal conformational changes relevant to the design of potent non-nucleoside inhibitors.
Primary Citation of Related Structures:   1RT1, 1RT2
PubMed Abstract: 
Crystal structures of HIV-1 reverse transcriptase (RT) complexed with a range of chemically diverse non-nucleoside inhibitors (NNIs) have shown a single pocket in which the inhibitors bind and details of the inhibitor-protein interactions. To delineate the structural requirements for an effective inhibitor, we have determined the structures of three closely related NNIs which vary widely in their potencies ...
Crystal structures of HIV-1 reverse transcriptase (RT) complexed with a range of chemically diverse non-nucleoside inhibitors (NNIs) have shown a single pocket in which the inhibitors bind and details of the inhibitor-protein interactions. To delineate the structural requirements for an effective inhibitor, we have determined the structures of three closely related NNIs which vary widely in their potencies. Crystal structures of HIV-1 RT complexed with two very potent inhibitors, MKC-442 and TNK-651, at 2.55 angstroms resolution complement our previous analysis of the complex with the less effective inhibitor, HEPT. These structures reveal conformational changes which correlate with changes in potency. We suggest that a major determinant of increased potency in the analogues of HEPT is an improved interaction between residue Tyr181 in the protein and the 6-benzyl ring of the inhibitors which stabilizes the structure of the complex. This arises through a conformational switching of the protein structure triggered by the steric bulk of the 5-substituent of the inhibitor pyrimidine ring.
Related Citations: 
Mechanism of Inhibition of HIV-1 Reverse Transcriptase by Non-Nucleoside Inhibitors Esnouf, R., Ren, J., Ross, C., Jones, Y., Stammers, D., Stuart, D. (1995) Nat Struct Biol 2: 303
High Resolution Structures of HIV-1 RT from Four RT-Inhibitor Complexes Ren, J., Esnouf, R., Garman, E., Somers, D., Ross, C., Kirby, I., Keeling, J., Darby, G., Jones, Y., Stuart, D., al., et (1995) Nat Struct Biol 2: 293
The Structure of HIV-1 Reverse Transcriptase Complexed with 9-Chloro-TIBO: Lessons for Inhibitor Design Ren, J., Esnouf, R., Hopkins, A., Ross, C., Jones, Y., Stammers, D., Stuart, D. (1995) Structure 3: 915
Crystals of HIV-1 Reverse Transcriptase Diffracting to 2.2 A Resolution Stammers, D.K., Somers, D.O., Ross, C.K., Kirby, I., Ray, P.H., Wilson, J.E., Norman, M., Ren, J.S., Esnouf, R.M., Garman, E.F., al., et (1994) J Mol Biol 242: 586
Organizational Affiliation: 
Laboratory of Molecular Biophysics, Rex Richards Building, Oxford, UK.