DNA polymerase alpha mutants from a Drosophila melanogaster cell line

Proc Natl Acad Sci U S A. 1980 Dec;77(12):7049-53. doi: 10.1073/pnas.77.12.7049.


Aphidicolin, a tetracyclic diterpenoid antibiotic, is a specific inhibitor of DNA synthesis in vivo and DNA polymerase (deoxynucleosidetriphosphate:DNA deoxynucleotidyltransferase, EC alpha of eukaryotic organisms. After ethyl methanesulfonate mutagenesis, we have recovered mutants of Drosophila melanogaster Schneider cell line no. 2 that grow at concentrations of aphidicolin that completely inhibit wild-type cells. The DNA polymerase alpha from one of these mutants, aph-10, is much more resistant to inhibition by the drug; the apparent Ki of the wild-type enzyme is 12 nM aphidicolin, whereas the apparent Ki of the aph-10 polymerase is more than 100 nM. (The apparent Km for dCTP is the same for both enzymes.) Another mutant, aph-13, overproduces DNA polymerase alpha at least 8-fold. The DNA polymerase of this mutant has the same apparent Km and Ki for dNTPs and aphidicolin as does wild-type polymerase.

Publication types

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

MeSH terms

  • Animals
  • Aphidicolin
  • Cell Line
  • DNA Replication / drug effects
  • DNA-Directed DNA Polymerase / genetics*
  • Diterpenes / pharmacology
  • Drosophila melanogaster / enzymology
  • Drosophila melanogaster / genetics*
  • Drug Resistance
  • Gene Expression Regulation
  • Mutation
  • Nucleic Acid Synthesis Inhibitors


  • Diterpenes
  • Nucleic Acid Synthesis Inhibitors
  • Aphidicolin
  • DNA-Directed DNA Polymerase