Conformational plasticity of the NNRTI-binding pocket in HIV-1 reverse transcriptase - A fluorine NMR study.
Related Articles Conformational plasticity of the NNRTI-binding pocket in HIV-1 reverse transcriptase - A fluorine NMR study.
Biochemistry. 2016 May 10;
Authors: Sharaf NG, Ishima R, Gronenborn AM
Abstract
HIV-1 reverse transcriptase (RT) is a major drug target in the treatment of HIV-1 infection. RT inhibitors currently in use include non-nucleoside, allosteric RT inhibitors (NNRTIs), which bind to a hydrophobic pocket, distinct from enzyme's active site. We investigated RT-NNRTI interactions by solution (19)F NMR, using singly (19)F labeled RT proteins. Comparison of (19)F chemical shifts of fluorinated RT and drug-resistant variants revealed that the fluorine resonance is a sensitive probe for identifying mutation-induced changes in the enzyme. Our data show that in the unliganded enzyme, the NNRTI-binding pocket is highly plastic and not locked into a single conformation. Upon inhibitor binding, the binding pocket rigidifies. In the inhibitor-bound state, the (19)F signal of RT is similar to that of drug-resistant mutant enzymes, distinct from what is observe for the free state. Our results demonstrate the power of (19)F NMR spectroscopy to characterize conformational properties using selectively (19)F labeled protein.
PMID: 27163463 [PubMed - as supplied by publisher]
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