Factor D is a selective single-stranded oligodeoxythymidine binding protein

Nucleic Acids Res. 1988 Jan 11;16(1):199-211. doi: 10.1093/nar/16.1.199.


Factor D, a protein purified from rabbit liver that selectively enhances traversal of template oligodeoxythymidine tracts by diverse DNA polymerases, was examined for the sequence specificity of its binding to DNA. Terminally [32P]-labeled oligomers with the sequence 5'-d[AATTC(N)16G]-3', N being dT, dA, dG, or dC, were interacted with purified factor D and examined for the formation of protein-DNA complexes that exhibit retarded electrophoretic mobility under nondenaturing conditions. Whereas significant binding of factor D to 5'-d[AATTC(T)16G]-3' is detected, there is no discernable association between this protein and oligomers that contain 16 contiguous moieties of dG, dA, or dC. Furthermore, factor D does not form detectable complexes with the duplexes oligo(dA).oligo(dT) or poly(dA).poly(dT). The preferential interaction of factor D with single-stranded poly(dT) is confirmed by experiments in which the polymerase-enhancing activity of this protein is protected by poly(dT) against heat inactivation two- and four-fold more efficiently than by poly(dA) or poly(dA).poly(dT), respectively.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • DNA, Single-Stranded / metabolism
  • DNA-Binding Proteins / isolation & purification
  • DNA-Binding Proteins / metabolism*
  • Kinetics
  • Liver / metabolism
  • Oligodeoxyribonucleotides / metabolism*
  • Rabbits
  • Templates, Genetic


  • DNA, Single-Stranded
  • DNA-Binding Proteins
  • Oligodeoxyribonucleotides
  • oligo (dT)