Misincorporation of dAMP opposite 2-hydroxyadenine, an oxidative form of adenine

Nucleic Acids Res. 1995 Mar 11;23(5):761-6. doi: 10.1093/nar/23.5.761.


Nucleotide incorporation opposite an oxidative form of adenine, 2-hydroxyadenine (2-OH-Ade) was investigated. When a primed template with 2-OH-Ade was treated with an exonuclease-deficient Klenow fragment of Escherichia coli DNA polymerase I (KFexo-), recombinant rat DNA polymerase beta (pol beta) or calf thymus DNA polymerase alpha (pol alpha), incorporation of dTMP and dAMP was observed. In addition, KFexo- inserted dGMP as well. A steady-state kinetic study indicated that the insertion of dAMP and dTMP opposite the DNA lesion occurred with similar frequency with KFexo- and pol beta. Insertion of dTMP opposite 2-OH-Ade was favored to that of dAMP by pol alpha. Chain extension from the A.2-OH-Ade pair is less favored than that from the T.2-OH-Ade pair by all three DNA polymerase. Analysis of full-length products of in vitro DNA synthesis showed that dTMP and dAMP were incorporated by DNA polymerases and that exonuclease-proficient and -deficient Klenow fragments also inserted dGMP opposite 2-OH-Ade. These results suggest that formation of 2-OH-Ade from A in DNA will induce A-->T and A-->C transversions in cells.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Base Composition
  • Base Sequence
  • DNA / chemical synthesis
  • DNA-Directed DNA Polymerase / chemistry
  • Deoxyadenine Nucleotides / chemistry*
  • Guanine / chemistry*
  • Kinetics
  • Molecular Sequence Data
  • Oxidation-Reduction
  • Rats


  • Deoxyadenine Nucleotides
  • Guanine
  • DNA
  • isoguanine
  • DNA-Directed DNA Polymerase