RNase H and A: Effects on DNA Template Specificity of RNA Polymerase From Normal and Friend Virus-Infected Mouse Spleen

Summary

DNA-dependent RNA polymerase was solubilized from nuclei of normal and Friend virus (FV)-infected mouse spleen by sonic disruption in the presence of 0.3m ammonium sulfate. The resulting enzyme activity was similar to that of RNA polymerase from other eukaryotic sources. Template specificity of the enzyme preparation differed notably from the 2 sources. The normal tissue preparation strongly preferred denatured DNA as its template, whereas the FV-infected tissue preparation preferred native DNA as its template. Interfering proteins and degradatory enzymes were detected, which may explain the difference in the RNA polymerase activities from normal and leukemic cells. The normal enzyme preparation had significant amounts of RNase A activity, whereas the FV-infected tissue had none. In addition, the preparation from FV-infected tissue had a large amount of RNase H activity, whereas the corresponding normal tissue had much less. The net result was an apparent DNA template specificity which was really a specificity of product degradation.