Purification and characterization of bacteriophage N4-induced DNA polymerase

J Biol Chem. 1988 Aug 15;263(23):11319-26.

Abstract

Coliphage N4 replication is independent of most host DNA replication functions except for the 5'----3' exonuclease activity of polA, DNA ligase, DNA gyrase, and ribonucleotide reductase (Guinta, D., Stambouly, J., Falco, S. C., Rist, J. K., and Rothman-Denes, L. B. (1986) Virology 150, 33-44). It is therefore expected that N4 codes for most of the functions required for replication of its genome. In this paper we report the purification of the N4-coded DNA polymerase from N4-infected cell extracts by following its activity on a gapped template and in an in vitro complementation system for N4 DNA replication (Rist, J. K., Pearle, M., Sugino, A., and Rothman-Denes, L. B. (1986) J. Biol. Chem. 261, 10506-10510). The enzyme is composed of one polypeptide, Mr 87,000. It is most active on templates containing short gaps synthesizing DNA with high fidelity in a quasi-processive manner. A strong 3'----5' exonuclease activity is associated with the DNA polymerase polypeptide. No 5'----3' exonuclease or strand-displacing activities were detected.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Coliphages / enzymology*
  • DNA Ligases / metabolism
  • DNA Replication
  • DNA-Directed DNA Polymerase / biosynthesis
  • DNA-Directed DNA Polymerase / isolation & purification*
  • Electrophoresis, Polyacrylamide Gel
  • Enzyme Induction
  • Molecular Weight
  • Temperature

Substances

  • DNA-Directed DNA Polymerase
  • DNA Ligases