Specific inhibition of DNA polymerase-associated RNase H by DNA

J Virol. 1977 Apr;22(1):243-6. doi: 10.1128/JVI.22.1.243-246.1977.


The RNase H activity associated with several RNA-directed DNA polymerases is inhibited by the addition of DNA, in contrast to RNase H activity from enzymes devoid of polymerizing activity. Kinetic investigations of the inhibitory effect of DNA, using purified Rauscher leukemia virus DNA polymerase as a test enzyme, revealed that the addition of DNA to an ongoing RNase H reaction causes an immediate cessation of RNase H activity. Concomitant initiation of DNA synthesis by inhibitory DNA can occur, provided that appropriate substrate and primer is available. Thus, in addition to providing a simple test for the distinction between polymerase-associated and polymerase-independent RNase H activity, this study strongly supports the concepts that (i) RNase H activity expressed by several mammalian oncoviral reverse transcriptases is an integral part of that molecule, and (ii) that the catalytic site of RNase H activity is also involuved in template-primer binding.

Publication types

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

MeSH terms

  • DNA / pharmacology
  • DNA, Viral / biosynthesis
  • Polynucleotides / pharmacology
  • RNA-Directed DNA Polymerase / metabolism*
  • Rauscher Virus / enzymology*
  • Rauscher Virus / metabolism
  • Ribonucleases / antagonists & inhibitors*
  • Ribonucleases / metabolism
  • Templates, Genetic


  • DNA, Viral
  • Polynucleotides
  • DNA
  • RNA-Directed DNA Polymerase
  • Ribonucleases