Interactions of the DNA polymerase X from African Swine Fever Virus with the ssDNA. Properties of the total DNA-binding site and the strong DNA-binding subsite

Biophys Chem. 2011 Sep;158(1):26-37. doi: 10.1016/j.bpc.2011.04.012. Epub 2011 Apr 28.


Interactions of the polymerase X from the African Swine Fever Virus with the ssDNA have been studied, using quantitative fluorescence titration and fluorescence resonance energy transfer techniques. The primary DNA-binding subsite of the enzyme, independent of the DNA conformation, is located on the C-terminal domain. Association of the bound DNA with the catalytic N-terminal domain finalizes the engagement of the total DNA-binding site of the enzyme and induces a large topological change in the structure of the bound ssDNA. The free energy of binding includes a conformational transition of the protein. Large positive enthalpy changes accompanying the ASFV pol X-ssDNA association indicate that conformational changes of the complex are induced by the engagement of the N-terminal domain. The enthalpy changes are offset by large entropy changes accompanying the DNA binding to the C-terminal domain and the total DNA-binding site, predominantly resulting from the release of water molecules.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • African Swine Fever Virus / enzymology*
  • Binding Sites
  • Catalytic Domain
  • DNA, Single-Stranded / chemistry*
  • DNA-Directed DNA Polymerase / chemistry*
  • Fluorescence Resonance Energy Transfer
  • Temperature
  • Thermodynamics
  • Water / chemistry


  • DNA, Single-Stranded
  • Water
  • DNA polymerase X
  • DNA-Directed DNA Polymerase