Effect of DNA modifications on DNA processing by HIV-1 integrase and inhibitor binding: role of DNA backbone flexibility and an open catalytic site

J Biol Chem. 2006 Oct 27;281(43):32428-38. doi: 10.1074/jbc.M605101200. Epub 2006 Aug 30.

Abstract

Integration of the viral cDNA into host chromosomes is required for viral replication. Human immunodeficiency virus integrase catalyzes two sequential reactions, 3'-processing (3'-P) and strand transfer (ST). The first integrase inhibitors are undergoing clinical trial, but interactions of inhibitors with integrase and DNA are not well understood in the absence of a co-crystal structure. To increase our understanding of integrase interactions with DNA, we examined integrase catalysis with oligonucleotides containing DNA backbone, base, and groove modifications placed at unique positions surrounding the 3'-processing site. 3'-Processing was blocked with substrates containing constrained sugars and alpha-anomeric residues, suggesting that integrase requires flexibility of the phosphodiester backbone at the 3'-P site. Of several benzo[a]pyrene 7,8-diol 9,10-epoxide (BaP DE) adducts tested, only the adduct in the minor groove at the 3'-P site inhibited 3'-P, suggesting the importance of the minor groove contacts for 3'-P. ST occurred in the presence of bulky BaP DE DNA adducts attached to the end of the viral DNA suggesting opening of the active site for ST. Position-specific effects of these BaP DE DNA adducts were found for inhibition of integrase by diketo acids. Together, these results demonstrate the importance of DNA structure and specific contacts with the viral DNA processing site for inhibition by integrase inhibitors.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, N.I.H., Intramural

MeSH terms

  • Base Sequence
  • Binding Sites
  • Catalysis
  • DNA / chemistry
  • DNA / metabolism*
  • DNA Adducts / chemistry
  • DNA Adducts / metabolism
  • DNA, Viral / chemistry
  • DNA, Viral / metabolism
  • Dihydroxydihydrobenzopyrenes / chemistry
  • Dihydroxydihydrobenzopyrenes / metabolism
  • Epoxy Compounds / chemistry
  • Epoxy Compounds / metabolism
  • HIV Integrase / metabolism*
  • HIV Integrase Inhibitors / chemistry
  • HIV Integrase Inhibitors / metabolism*
  • HIV Integrase Inhibitors / pharmacology
  • HIV-1 / enzymology*
  • HIV-1 / genetics
  • Humans
  • Models, Chemical
  • Models, Molecular
  • Molecular Sequence Data
  • Molecular Structure
  • Nucleic Acid Conformation
  • Oligonucleotides / chemistry
  • Oligonucleotides / metabolism
  • Pliability
  • Substrate Specificity
  • Virus Integration

Substances

  • DNA Adducts
  • DNA, Viral
  • Dihydroxydihydrobenzopyrenes
  • Epoxy Compounds
  • HIV Integrase Inhibitors
  • Oligonucleotides
  • DNA
  • HIV Integrase