Journal ArticleDOI
Phenotypic mechanism of HIV-1 resistance to 3'-azido-3'-deoxythymidine (AZT): increased polymerization processivity and enhanced sensitivity to pyrophosphate of the mutant viral reverse transcriptase.
TLDR
It is proposed that HIV-1 resistance to AZT results from the selectively decreased binding of AZTTP and the increased pyroph phosphorolytic cleavage of chain-terminated viral DNA by the mutant RT at physiological pyrophosphate levels, resulting in a net decrease in chain termination.Abstract:
The multiple mutations associated with high-level AZT resistance (D67N, K70R, T215F, K219Q) arise in two separate subdomains of the viral reverse transcriptase (RT), suggesting that these mutations may contribute differently to overall resistance. We compared wild-type RT with the D67N/K70R/T215F/K219Q, D67N/K70R, and T215F/K219Q mutant enzymes. The D67N/K70R/T215F/K219Q mutant showed increased DNA polymerase processivity; this resulted from decreased template/primer dissociation from RT, and was due to the T215F/K219Q mutations. The D67N/K70R/T215F/K219Q mutant was less sensitive to AZTTP (IC50 approximately 300 nM) than wt RT (IC50 approximately 100 nM) in the presence of 0.5 mM pyrophosphate. This change in pyrophosphate-mediated sensitivity of the mutant enzyme was selective for AZTTP, since similar Km values for TTP and inhibition by ddCTP and ddGTP were noted with wt and mutant RT in the absence or in the presence of pyrophosphate. The D67N/K70R/T215F/K219Q mutant showed an increased rate of pyrophosphorolysis (the reverse reaction of DNA synthesis) of chain-terminated DNA; this enhanced pyrophosphorolysis was due to the D67N/K70R mutations. However, the processivity of pyrophosphorolysis was similar for the wild-type and mutant enzymes. We propose that HIV-1 resistance to AZT results from the selectively decreased binding of AZTTP and the increased pyrophosphorolytic cleavage of chain-terminated viral DNA by the mutant RT at physiological pyrophosphate levels, resulting in a net decrease in chain termination. The increased processivity of viral DNA synthesis may be important to enable facile HIV replication in the presence of AZT, by compensating for the increased reverse reaction rate.read more
Citations
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Journal ArticleDOI
HIV-1 Antiretroviral Drug Therapy
Eric J. Arts,Daria J. Hazuda +1 more
TL;DR: The basic principles of antiretroviral drug therapy, the mode of drug action, and the factors leading to treatment failure are reviewed (i.e., drug resistance).
Journal ArticleDOI
HIV drug resistance.
François Clavel,Allan J. Hance +1 more
TL;DR: Combinations of antiretroviral drugs have proven remarkably effective in controlling the progression of HIV disease and prolonging survival, but these benefits can be compromised by the development of drug resistance.
Journal ArticleDOI
Antiretroviral drug resistance testing in adults infected with human immunodeficiency virus type 1: 2003 recommendations of an International AIDS Society-USA Panel.
Martin S. Hirsch,Françoise Brun-Vézinet,Bonaventura Clotet,Brian Conway,Daniel R. Kuritzkes,Richard T. D'Aquila,Lisa M. Demeter,Scott M. Hammer,Victoria A. Johnson,Clive Loveday,John W. Mellors,Donna M. Jacobsen,Douglas D. Richman +12 more
TL;DR: The International AIDS Society-USA convened a panel of physicians and scientists with expertise in antiretroviral drug management, HIV-1 drug resistance, and patient care to provide updated recommendations for HIV- 1 resistance testing.
Journal ArticleDOI
Structure and function of HIV-1 reverse transcriptase: molecular mechanisms of polymerization and inhibition.
Stefan G. Sarafianos,Bruno Marchand,Kalyan Das,Daniel M. Himmel,Michael A. Parniak,Stephen H. Hughes,Edward Arnold +6 more
TL;DR: A better understanding of the structure and function of RT and of the mechanism(s) of inhibition can be used to generate better drugs; in particular, drugs that are effective against the current drug-resistant strains of HIV-1.
Journal ArticleDOI
The structural biology of HIV-1: mechanistic and therapeutic insights.
Alan Engelman,Peter Cherepanov +1 more
TL;DR: Recent advances in HIV-1 structural biology are reviewed, focusing on the molecular mechanisms of viral replication and on the development of new therapeutics.
References
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Locations of anti-AIDS drug binding sites and resistance mutations in the three-dimensional structure of HIV-1 reverse transcriptase. Implications for mechanisms of drug inhibition and resistance
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TL;DR: A study of steady-state kinetics of polymerization by purified human immunodeficiency virus DNA polymerase (reverse transcriptase) has been conducted and a heterologous polynucleotide, poly(rC), is a potent inhibitor of the enzyme.
Journal ArticleDOI
Prevalence and Clinical Significance of Zidovudine Resistance Mutations in Human Immunodeficiency Virus Isolated from Patients after Long-Term Zidovudine Treatment
A. J. Japour,Seth L. Welles,Richard T. D'Aquila,Victoria A. Johnson,D. D. Richman,Robert W. Coombs,Patricia Reichelderfer,James O. Kahn,Clyde S. Crumpacker,Daniel R. Kuritzkes +9 more
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