Subspecies of DNA polymerase alpha from calf thymus with different fidelity in copying synthetic template-primers

Nucleic Acids Res. 1983 Jan 11;11(1):193-202. doi: 10.1093/nar/11.1.193.

Abstract

Three different subspecies of DNA polymerase alpha from calf thymus sedimenting at 9 S, 7 S and 5.7 S have been investigated with respect to their accuracy of in vitro DNA synthesis on poly (dA) (dT)16 and poly d(AT) as template-primers. Our results indicate that the structure of DNA polymerase alpha has a strong influence on the accuracy of DNA synthesis. The 9 S enzyme shows a misincorporation frequency of about 1:100 000. An error rate of 1:15 000 is measured for the 7 S species. The 5.7 S enzyme for which an error rate of 1:3 000 is determined, has to be considered as error prone. Lowering the rate of DNA synthesis leads to a decrease in fidelity. The single stranded DNA binding protein from E.coli increases the accuracy of the 5.7 S and the 7 S enzyme by a factor of two. Mn2+ decreases the fidelity of all three subspecies in a concentration dependent manner.

MeSH terms

  • Animals
  • Cattle
  • DNA Polymerase II / metabolism*
  • DNA Replication
  • DNA-Directed DNA Polymerase / metabolism*
  • Isoenzymes / metabolism
  • Kinetics
  • Manganese / pharmacology
  • Substrate Specificity
  • Templates, Genetic
  • Thymus Gland / enzymology*

Substances

  • Isoenzymes
  • Manganese
  • DNA Polymerase II
  • DNA-Directed DNA Polymerase