Molecular dynamics study of HIV-1 RT-DNA-nevirapine complexes explains NNRTI inhibition and resistance by connection mutations

Authors

  • R. S. K. Vijayan,

    1. Center for Advanced Biotechnology and Medicine, Rutgers University, Piscataway, New Jersey
    2. Department of Chemistry and Chemical Biology, Rutgers University, Piscataway, New Jersey
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  • Eddy Arnold,

    1. Center for Advanced Biotechnology and Medicine, Rutgers University, Piscataway, New Jersey
    2. Department of Chemistry and Chemical Biology, Rutgers University, Piscataway, New Jersey
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  • Kalyan Das

    Corresponding author
    1. Center for Advanced Biotechnology and Medicine, Rutgers University, Piscataway, New Jersey
    2. Department of Chemistry and Chemical Biology, Rutgers University, Piscataway, New Jersey
    • Correspondence to: K. Das; Center for Advanced Biotechnology and Medicine, Rutgers University, Piscataway, New Jersey 08854. E-mail: kalyan@cabm.rutgers.edu

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ABSTRACT

HIV-1 reverse transcriptase (RT) is a multifunctional enzyme that is targeted by nucleoside analogs (NRTIs) and non-nucleoside RT inhibitors (NNRTIs). NNRTIs are allosteric inhibitors of RT, and constitute an integral part of several highly active antiretroviral therapy regimens. Under selective pressure, HIV-1 acquires resistance against NNRTIs primarily by selecting mutations around the NNRTI pocket. Complete RT sequencing of clinical isolates revealed that spatially distal mutations arising in connection and the RNase H domain also confer NNRTI resistance and contribute to NRTI resistance. However, the precise structural mechanism by which the connection domain mutations confer NNRTI resistance is poorly understood. We performed 50-ns molecular dynamics (MD) simulations, followed by essential dynamics, free-energy landscape analyses, and network analyses of RT-DNA, RT-DNA-nevirapine (NVP), and N348I/T369I mutant RT-DNA-NVP complexes. MD simulation studies revealed altered global motions and restricted conformational landscape of RT upon NVP binding. Analysis of protein structure network parameters demonstrated a dissortative hub pattern in the RT-DNA complex and an assortative hub pattern in the RT-DNA-NVP complex suggesting enhanced rigidity of RT upon NVP binding. The connection subdomain mutations N348I/T369I did not induce any significant structural change; rather, these mutations modulate the conformational dynamics and alter the long-range allosteric communication network between the connection subdomain and NNRTI pocket. Insights from the present study provide a structural basis for the biochemical and clinical findings on drug resistance caused by the connection and RNase H mutations. Proteins 2014; 82:815–829. © 2013 Wiley Periodicals, Inc.

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