Searching for target sequences by p53 protein is influenced by DNA length

Biochem Biophys Res Commun. 2006 Mar 10;341(2):470-7. doi: 10.1016/j.bbrc.2005.12.202. Epub 2006 Jan 11.


One of the most important functions of the tumor suppressor p53 protein is its sequence-specific binding to DNA. Using a competition assay on agarose gels we found that the p53 consensus sequences in longer DNA fragments are better targets than the same sequences in shorter DNAs. Semi-quantitative evaluation of the competition experiments showed a correlation between the relative p53-DNA binding and the DNA lengths. Our results are consistent with a model of the p53-DNA interactions involving one-dimensional migration of the p53 protein along the DNA for distances of about 1000 bp while searching for its target sites. Positioning of the p53 target in the DNA fragment did not substantially affect the apparent p53-DNA binding, suggesting that p53 can slide along the DNA in a bi-directional manner. In contrast to full-length p53, the isolated core domain did not show any significant correlation between sequence-specific DNA binding and fragment length.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Binding Sites
  • Binding, Competitive
  • DNA / chemistry
  • DNA / genetics*
  • DNA Restriction Enzymes / metabolism
  • Electrophoresis, Agar Gel
  • Genes, p53*
  • Humans
  • Models, Statistical
  • Plasmids / metabolism
  • Protein Structure, Tertiary
  • Recombinant Proteins / chemistry
  • Time Factors
  • Tumor Suppressor Protein p53 / genetics*


  • Recombinant Proteins
  • TP53 protein, human
  • Tumor Suppressor Protein p53
  • DNA
  • DNA Restriction Enzymes