Effects of 8-chlorodeoxyadenosine on DNA synthesis by the Klenow fragment of DNA polymerase I

Bioorg Med Chem Lett. 2003 May 5;13(9):1509-12. doi: 10.1016/s0960-894x(03)00204-x.


8-chloro-2'-deoxyadenosine (8-Cl-dAdo) was incorporated into synthetic DNA oligonucleotides to determine its effects on DNA synthesis by the 3'-5' exonuclease-free Klenow fragment of Escherichia coli DNA Polymerase I (KF-). Single nucleotide insertion experiments were used to determine the coding potential of 8-Cl-dAdo in a DNA template. KF- inserted TTP opposite 8-Cl-dAdo in the template, but with decreased efficiency relative to natural deoxyadenosine. Running-start primer extensions with KF- resulted in polymerase pausing at 8-Cl-dAdo template sites during DNA synthesis. The 2'-deoxyribonucleoside triphosphate analogue, 8-Cl-dATP, was incorporated opposite thymidine (T) approximately two-fold less efficiently than dATP.

Publication types

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

MeSH terms

  • DNA / chemical synthesis*
  • DNA Polymerase I / chemistry*
  • Deoxyadenosines / pharmacology*
  • Escherichia coli / chemistry
  • Oligonucleotides / chemistry*
  • Thymidine / chemistry


  • 8-chlorodeoxyadenosine
  • Deoxyadenosines
  • Oligonucleotides
  • DNA
  • DNA Polymerase I
  • Thymidine