Detection of an epitope, not required for polymerization, that is conserved between E.coli DNA polymerases I and III and bacteriophage T4 DNA polymerase

Nucleic Acids Res. 1988 Jul 25;16(14A):6353-60. doi: 10.1093/nar/16.14.6353.


Monoclonal antibodies directed against the alpha subunit of the DNA polymerase III holoenzyme (1) of E. coli were tested for cross-reactivity with a variety of polymerases. We found that one monoclonal antibody bound to E. coli DNA polymerase I as well as to DNA polymerase III. A weaker, but specific, interaction was also detected with T4 DNA polymerase. We exploited the proteolysis procedure developed by Setlow, Brutlag and Kornberg (2) to determine which domain of DNA polymerase I contained the conserved epitope. Contrary to expectations, it was not found in the polymerase domain, but in the 5'----3' exonuclease domain. This reveals a sequence or structure, sufficiently important to be conserved among these polymerases, that is not directly involved in the polymerization reaction.

Publication types

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

MeSH terms

  • Antibodies, Monoclonal / immunology
  • Cross Reactions
  • DNA / biosynthesis
  • DNA Polymerase I / immunology*
  • DNA Polymerase III / immunology*
  • DNA-Directed DNA Polymerase / immunology*
  • Epitopes
  • Immunosorbent Techniques
  • T-Phages / enzymology


  • Antibodies, Monoclonal
  • Epitopes
  • DNA
  • DNA Polymerase I
  • DNA Polymerase III
  • DNA-Directed DNA Polymerase