Purification and characterization of a DNA polymerase from the archaebacterium Thermoplasma acidophilum

Eur J Biochem. 1990 Jul 5;190(3):517-21. doi: 10.1111/j.1432-1033.1990.tb15604.x.


A thermophilic DNA polymerase has been purified to near homogeneity from the archaebacterium Thermoplasma acidophilum. Analysis of the purified enzyme by sodium dodecyl sulfate gel electrophoresis revealed a single polypeptide of 88 kDa which co-sediments with the DNA polymerase activity on sucrose gradients. Combination of sedimentation and gel filtration analyses indicates that this DNA polymerase is an 88-kDa monomeric enzyme in its native form. The DNA polymerase is resistant to aphidicolin, slightly sensitive to 2',3'-dideoxyribosylthymine triphosphate and inhibited by N-ethylmaleimide when preincubation with this reagent is performed at 65 degrees C. We find that a 3'----5' exonuclease activity is associated with the purified DNA polymerase; the two activities of the enzyme are optimal at 65 degrees C but the exonuclease activity is active in a broader range of lower temperatures and is more thermostable than the DNA polymerase activity.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Archaea / enzymology*
  • Bacteria / enzymology*
  • Centrifugation, Density Gradient
  • Chromatography, Affinity
  • Chromatography, Ion Exchange
  • DNA-Directed DNA Polymerase / isolation & purification*
  • DNA-Directed DNA Polymerase / metabolism
  • Hot Temperature
  • Kinetics
  • Macromolecular Substances
  • Molecular Weight
  • Templates, Genetic


  • Macromolecular Substances
  • DNA-Directed DNA Polymerase