Differential removal of thymidine nucleotide analogues from blocked DNA chains by human immunodeficiency virus reverse transcriptase in the presence of physiological concentrations of 2'-deoxynucleoside triphosphates

Antimicrob Agents Chemother. 2000 Dec;44(12):3465-72. doi: 10.1128/aac.44.12.3465-3472.2000.


Removal of 2',3'-didehydro-3'-deoxythymidine-5'-monophosphate (d4TMP) from a blocked DNA chain can occur through transfer of the chain-terminating residue to a nucleotide acceptor by human immunodeficiency virus type 1 (HIV-1) reverse transcriptase (RT). ATP-dependent removal of either d4TMP or 3'-azido-3'-deoxythymidine-5'-monophosphate (AZTMP) is increased in AZT resistant HIV-1 RT (containing D67N/K70R/T215F/K219Q mutations). Removal of d4TMP is strongly inhibited by the next complementary deoxynucleoside triphosphate (50% inhibitory concentration [IC(50)] of approximately 0.5 microM), whereas removal of AZTMP is much less sensitive to this inhibition (IC(50) of >100 microM). This could explain the lack of cross-resistance by AZT-resistant HIV-1 to d4T in phenotypic drug susceptibility assays.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adenosine Triphosphate / metabolism
  • DNA Primers / metabolism*
  • Dideoxynucleotides
  • HIV Reverse Transcriptase / drug effects
  • HIV Reverse Transcriptase / metabolism*
  • Reverse Transcriptase Inhibitors / pharmacology
  • Stavudine / analogs & derivatives*
  • Stavudine / metabolism*
  • Stavudine / pharmacology
  • Templates, Genetic
  • Thymidine Monophosphate / analogs & derivatives
  • Thymidine Monophosphate / metabolism
  • Thymine Nucleotides / metabolism
  • Thymine Nucleotides / pharmacology
  • Zidovudine / analogs & derivatives*
  • Zidovudine / metabolism
  • Zidovudine / pharmacology


  • 2',3'-dideoxy-2',3'-didehydrothymidine monophosphate
  • DNA Primers
  • Dideoxynucleotides
  • Reverse Transcriptase Inhibitors
  • Thymine Nucleotides
  • 3'-azido-3'-deoxythymidine 5'phosphate
  • Thymidine Monophosphate
  • Zidovudine
  • Adenosine Triphosphate
  • Stavudine
  • HIV Reverse Transcriptase