Printcd in U.S.A. Enzymatic Synthesis of Deoxyribonucleic Acid IX. THE POLYMERASE FORMED AFTER T2 BACTERIOPHAGE INFECTION OF ESCHERICHIA COLI: A NEW ENZYME*?

The synthesis of T2 bacteriophage deoxyribonucleic acid is now known to depend on the development of a series of new enzymes which are undetectable in uninfected Escherichia coli (2-7). An augmented rate of deoxyribonucleic acid synthesis also occurs (8) which is accompanied by an approximately 10-fold increase in polymerase activity in extracts of these cells, aa compared with extracts of uninfected cells (3). In order to observe this increase in polymerase activity, it was essential to assay the enzyme with a heated deoxyribonucleic acid primer; the requirement for a heated primer is not demonstrable for the polymerase activity in extracts of uninfected cells. An impor-tant question regarding the augmented polymerase level was whether it was due to the increased production of the pre-exist-ing E. coli polymerase or to the synthesis of a totally new phage-directed enzyme. Koerner, Smith, and Buchanan (6) have als