Bacteriophage T7 deoxyribonucleic acid replication invitro. Bacteriophage T7 DNA polymerase: an an emzyme composed of phage- and host-specific subunits.

Journal Article (Journal Article)

The DNA polymerase induced after infection of Escherichia coli by phage T7 has been purified 500-fold to near homogeneity as judged by polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate. The purified enzyme complements extracts of cells infected with a T7 gene 5 mutant to permit cell-free replication of duplex T7 DNA. In contrast, purified T4 DNA polymerase or E. coli DNA polymerase I is unable to do so, thus suggesting a specific requirement for the T7 enzyme in the replication of the viral DNA. E. coli TsnC protein is present in purified T7 DNA polymerase in one-to-one stoichiometry with T7 gene 5 protein, and can be isolated in homogeneous form from heat-denatured enzyme by chromatography on DEAE-cellulose. The inactive form of T7 gene 5 protein that accumulates in tsnC hosts has been partially purified. When partially purified gene 5 protein is mixed with purified TsnC protein, DNA polymerase activity is restored, and formation of a one-to-one complex between the two proteins occurs. These results indicate that the functional form ofT7 DNA polymerase is a complex composed of phage- and host-specified subunits.

Full Text

Duke Authors

Cited Authors

  • Modrich, P; Richardson, CC

Published Date

  • July 25, 1975

Published In

Volume / Issue

  • 250 / 14

Start / End Page

  • 5515 - 5522

PubMed ID

  • 1095579

International Standard Serial Number (ISSN)

  • 0021-9258


  • eng

Conference Location

  • United States