In vitro DNA synthesis in the presence of antibody to homogeneous E. Coli DNA polymerase

After the addition of antiserum against E. Coli DNA polymerase to soluble extracts of the DNA polymerase-defective mutant (Pol A<SUB>1</SUB><SUP>-</SUP>) or the parent strain a DNA synthesizing activity is still present. The antiserum-resistant activity in both the mutant and parent strain has similar requirements: four deoxynucleoside triphosphates, Mg<SUP>++</SUP>, and a double-stranded DNA primer. The rates of heat denaturation and the effects of the addition of ethanol and potassium chloride are similar for the antiserum-resistant activities, and differ from the antiserum-sensitive activity of the parent strain and homogeneous E. Coli DNA polymerase. Thus, the presence of an additional soluble DNA polymerizing enzyme in E. Coli is indicated