Characterization of human cytomegalovirus-induced DNA polymerase and the associated 3'-to-5', exonuclease

Virology. 1983 Jan 30;124(2):221-31. doi: 10.1016/0042-6822(83)90339-2.


A DNA polymerase activity induced by human cytomegalovirus (HCMV) was separated from host cell DNA polymerase and purified by phosphocellulose and DNA-cellulose column chromatography. The DNA polymerase activity was strongly inhibited by phosphonoacetic acid, aphidicolin, araATP, and N-ethylmaleimide, but it was resistant to 2',3'-dideoxyTTP. The sensitivity of HCMV-induced DNA polymerase to these reagents resembles that of host cell DNA polymerase alpha. However, HCMV-induced DNA polymerase activity was stimulated several fold by 100 mM ammonium sulfate, by which DNA polymerase alpha activity was strongly inhibited. Furthermore, it was found that a 3'-to-5' exonuclease activity was tightly associated with the HCMV-induced DNA polymerase. The exonuclease was also stimulated by ammonium sulfate, was inhibited by phosphoacetic acid, and it preferred single-stranded DNA as a substrate. The results suggest that the 3'-to-5' exonuclease may play a role in proofreading in the polymerization process as an integral part of the HCMV-induced DNA polymerase.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Ammonium Sulfate / pharmacology
  • Aphidicolin
  • Cytomegalovirus / enzymology*
  • DNA, Single-Stranded / metabolism
  • DNA-Directed DNA Polymerase / isolation & purification
  • DNA-Directed DNA Polymerase / metabolism*
  • Diterpenes / pharmacology
  • Ethylmaleimide / pharmacology
  • Exodeoxyribonuclease V
  • Exodeoxyribonucleases / isolation & purification
  • Exodeoxyribonucleases / metabolism*
  • Hydrogen-Ion Concentration
  • Phosphonoacetic Acid / pharmacology
  • Substrate Specificity
  • Vidarabine Phosphate / analogs & derivatives
  • Vidarabine Phosphate / pharmacology


  • DNA, Single-Stranded
  • Diterpenes
  • Vidarabine Phosphate
  • ara-ATP
  • Aphidicolin
  • DNA-Directed DNA Polymerase
  • Exodeoxyribonucleases
  • Exodeoxyribonuclease V
  • Phosphonoacetic Acid
  • Ethylmaleimide
  • Ammonium Sulfate