Thermostable DNA polymerase from Thermus thermophilus B35: influence of divalent metal ions on the interaction with deoxynucleoside triphosphates

Biochemistry (Mosc). 2000 May;65(5):609-14.

Abstract

The interaction of DNA polymerase from Thermus thermophilus B35 (Tte-pol) with deoxynucleoside triphosphates in the presence of different divalent metal ions has been studied. DNA synthesis and competitive inhibition of the polymerase reaction by non-complementary dNTPs are described with corresponding kinetic schemes. The co-factor properties of some metals (Mg2+, Mn2+, Co2+, Ni2+, Cu2+, Ca2+, Cd2+, and Zn2+) were investigated, and their activating concentration ranges were determined. It was found that kcat values are significantly decreased and Km values slowly decrease when Mn2+ displaces Mg2+. The value of Kd for DNA template-primer is Me2+-independent, whereas Kd values for non-complementary dNTPs decrease in the presence of Mn2+. Tte-pol processivity but not DNA synthesis efficiency is Me2+-type independent.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cations, Divalent
  • DNA-Directed DNA Polymerase / chemistry
  • DNA-Directed DNA Polymerase / genetics
  • DNA-Directed DNA Polymerase / metabolism*
  • Deoxyribonucleotides / metabolism*
  • Enzyme Stability
  • Kinetics
  • Mutagenesis, Site-Directed
  • Protein Binding
  • Thermus thermophilus / enzymology*
  • X-Ray Diffraction

Substances

  • Cations, Divalent
  • Deoxyribonucleotides
  • DNA-Directed DNA Polymerase