Separation of [formula omitted] ribonucleases on a DNA agarose column and the identification of an RNase H activity

Abstract

Single stranded DNA agarose columns can be used to separate Escherichia , coli ribonucleases from the bulk of the cellular proteins. By successive chromatography on DNA agarose, hydroxylapatite and DEAE cellulose, separation of the enzymes ribonuclease II, III, H and polynucleotide phosphorylase from one another was made possible. Ribonuclease II can be purified by this technique at least as well as by any of the other existing techniques. These experiments also confirmed the existence in E . coli of a recently reported enzyme, RNase H, which can degrade RNA in RNA-DNA hybrids. Thus DNA agarose seems to be a useful early step in the purification of Escherichia , coli ribonucleases.