Effect of divalent and monovalent cations on calf thymus PCNA-independent DNA polymerase delta and its 3'----5' exonuclease

FEBS Lett. 1990 Jan 1;259(2):349-52. doi: 10.1016/0014-5793(90)80045-k.


Recent data suggest that DNA polymerases alpha and delta might have a coordinate functional role at the replication fork. In this communication we show that Mg2+ is likely the natural metal activator for both enzymes. Mn2+, a known mutagenic agent, is a competitive inhibitor of Mg2+ for DNA polymerase delta and acompetitive for DNA polymerase alpha. The 3'----5' exonuclease activity associated with DNA polymerase delta is not affected upon addition of Mn2+. Be2+, another mutagenic agent, on the other hand, has an inhibitory effect on the 3'----5' exonuclease, but not on the DNA polymerase delta. The data presented might explain the mutagenic and carcinogenic potential of these two divalent cations.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cations, Divalent
  • Cations, Monovalent
  • Cattle
  • DNA Polymerase II / isolation & purification
  • DNA Polymerase II / metabolism
  • DNA Polymerase III
  • DNA-Directed DNA Polymerase / isolation & purification
  • DNA-Directed DNA Polymerase / metabolism*
  • Endodeoxyribonucleases / metabolism*
  • Kinetics
  • Nuclear Proteins / physiology*
  • Proliferating Cell Nuclear Antigen
  • Thymus Gland / enzymology*


  • Cations, Divalent
  • Cations, Monovalent
  • Nuclear Proteins
  • Proliferating Cell Nuclear Antigen
  • DNA Polymerase II
  • DNA Polymerase III
  • DNA-Directed DNA Polymerase
  • Endodeoxyribonucleases
  • deoxyribonuclease V