DNA polymerase III from Saccharomyces cerevisiae. II. Inhibitor studies and comparison with DNA polymerases I and II

J Biol Chem. 1988 Jan 15;263(2):925-30.


The newly identified yeast DNA polymerase III was compared to DNA polymerases I and II and the mitochondrial DNA polymerase. Inhibition by aphidicolin (I50) of DNA polymerases I, II, and III was 4, 6, and 0.6 micrograms/ml, respectively. The mitochondrial enzyme was insensitive to the drug. N2-(p-n-butylphenyl)-2'-deoxyguanosine 5'-triphosphate strongly inhibited DNA polymerase I (I50 = 0.3 microM), whereas DNA polymerase III was less sensitive (I50 = 80 microM). Conditions that allowed proteolysis to proceed during the preparation of extracts converted DNA polymerase II from a sensitive form (I50 = 2.4 microM) to a resistant form (I50 = 2 mM). The mitochondrial DNA polymerase is insensitive (I50 greater than 5 mM). With most other inhibitors tested (N-ethylmaleimide, heparin, salt) only small differences were observed between the three nuclear DNA polymerases. Polyclonal antibodies to DNA polymerase III did not inhibit DNA polymerases I and II, nor were those polymerases recognized by Western blotting. Monoclonal antibodies to DNA polymerase I did not crossreact with DNA polymerases II and III. The results show that DNA polymerase III is distinct from DNA polymerase I and II.

Publication types

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

MeSH terms

  • Antibodies, Monoclonal
  • Aphidicolin
  • DNA Polymerase I / antagonists & inhibitors*
  • DNA Polymerase II / antagonists & inhibitors*
  • DNA Polymerase III / antagonists & inhibitors*
  • Deoxyguanine Nucleotides / pharmacology
  • Diterpenes / pharmacology
  • Kinetics
  • Nucleic Acid Synthesis Inhibitors*
  • Saccharomyces cerevisiae / enzymology*


  • Antibodies, Monoclonal
  • Deoxyguanine Nucleotides
  • Diterpenes
  • Nucleic Acid Synthesis Inhibitors
  • Aphidicolin
  • N(2)-(4-n-butylphenyl)-2'-deoxyguanosine 5'-triphosphate
  • DNA Polymerase I
  • DNA Polymerase II
  • DNA Polymerase III