Deoxyribonucleic acid polymerase from the extreme thermophile Thermus aquaticus

J Bacteriol. 1976 Sep;127(3):1550-7. doi: 10.1128/jb.127.3.1550-1557.1976.


A stable deoxyribonucleic acid (DNA) polymerase (EC with a temperature optimum of 80 degrees C has been purified from the extreme thermophile Thermus aquaticus. The enzyme is free from phosphomonoesterase, phosphodiesterase and single-stranded exonuclease activities. Maximal activity of the enzyme requires all four deoxyribonucleotides and activated calf thymus DNA. An absolute requirement for divalent cation cofactor was satisfied by Mg2+ or to a lesser extent by Mn2+. Monovalent cations at concentrations as high as 0.1 M did not show a significant inhibitory effect. The pH optimum was 8.0 in tris(hydroxymethyl)aminomethane-hydrochloride buffer. The molecular weight of the enzyme was estimated by sucrose gradient centrifugation and gel filtrations on Sephadex G-100 to be approximately 63,000 to 68,000. The elevated temperature requirement, small size, and lack of nuclease activity distinguish this polymerase from the DNA polymerase of Escherichia coli.

MeSH terms

  • Bacteria / enzymology*
  • DNA Nucleotidyltransferases / isolation & purification
  • DNA Nucleotidyltransferases / metabolism*
  • Deoxyribonucleotides / pharmacology
  • Hot Temperature
  • Hydrogen-Ion Concentration
  • Magnesium / pharmacology
  • Manganese / pharmacology
  • Molecular Weight
  • Potassium Chloride / pharmacology
  • Sodium Chloride / pharmacology


  • Deoxyribonucleotides
  • Manganese
  • Sodium Chloride
  • Potassium Chloride
  • DNA Nucleotidyltransferases
  • Magnesium