The structural gene for deoxyribonucleic acid polymerase in bacteriophages T4 and T5.

Abstract

T4 amber mutants known to be defective in DNA synthesis were screened for their ability to induce the T4 DNA polymerase. Of the mutants examined, only those which are associated with gene 43 were found to be defective in the synthesis of this enzyme. A polymerase with greater heat-lability than that induced by wild-type T4 was partially purified from cells of E. coli which had been infected with a temperature-sensitive mutant, is L91, known to map in gene 43. A DNA polymerase, which was relatively more heat-labile than the enzyme induced by the wild-type phage, was also purified from cells of E. coli infected with a temperature-sensitive mutant (ts 53) of T5. These findings indicate that gene 43 represents the structural gene for the T4 DNA polymerase and that the gene in which mutant ts 53 is defective is the structural gene for the T5 DNA polymerase.