Characterization of DNA polymerase beta mutants with amino acid substitutions located in the C-terminal portion of the enzyme

Mol Gen Genet. 1995 Jul 28;248(2):217-24. doi: 10.1007/BF02190803.


We used quantitative complementation assays to characterize individual DNA polymerase beta (Pol beta) mutants for their ability to function in DNA replication and DNA repair. We also describe a screen for detecting mutator activity of DNA polymerase beta mutants. By using these bioassays, together with DNA polymerase activity gels, we characterized 15 new DNA polymerase beta mutants that display a wide spectrum of phenotypes. Most of these mutants are generally defective in their ability to synthesize DNA. However, two of our Pol beta mutants show more complex phenotypes: they are able to function in DNA repair but unable to participate in DNA replication. One of our mutants displays mutator activity in vivo. Our work provides a model to study mutant mammalian enzymes in Escherichia coli with phenotypes that are otherwise difficult to assess.

Publication types

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

MeSH terms

  • Animals
  • Blotting, Western
  • DNA Polymerase I / chemistry
  • DNA Polymerase I / genetics*
  • DNA Polymerase I / metabolism
  • DNA Repair
  • DNA Replication
  • Escherichia coli / genetics
  • Genetic Complementation Test
  • Methyl Methanesulfonate / pharmacology
  • Mutagenesis
  • Mutation
  • Nitrous Acid / pharmacology
  • Phenotype
  • Rats


  • Methyl Methanesulfonate
  • DNA Polymerase I
  • Nitrous Acid