Mechanical and structural properties of YOYO-1 complexed DNA

Nucleic Acids Res. 2010 Oct;38(19):6526-32. doi: 10.1093/nar/gkq434. Epub 2010 May 28.


YOYO-1 is a fluorescent dye widely used for probing the statistical-mechanical properties of DNA. However, currently contradicting data exist how YOYO-1 binding alters the DNA structure and rigidity. Here, we systematically address this problem using magnetic tweezers. Remarkably, we find that the persistence length of DNA remains constant independent of the amount of bound YOYO-1, which contrasts previous assumptions. While the ionic conditions can considerably alter the stability of YOYO-1 binding, the DNA bending rigidity seems not to be affected. We furthermore determine important structural parameters such as the binding site size, the elongation, as well as the untwisting angle per bound YOYO-1 molecule. We expect that our assay, in which all the parameters are determined within a single experiment, will be beneficial for a large range of other DNA binding drugs.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Benzoxazoles / chemistry*
  • Binding Sites
  • DNA / chemistry*
  • Fluorescent Dyes / chemistry*
  • Intercalating Agents / chemistry*
  • Osmolar Concentration
  • Quinolinium Compounds / chemistry*


  • Benzoxazoles
  • Fluorescent Dyes
  • Intercalating Agents
  • Quinolinium Compounds
  • 1,1'-((4,4,7,7-tetramethyl)-4,7-diazaundecamethylene)bis-4-(3-methyl-2,3-dihydro(benzo-1,3-oxazole)-2-methylidene)quinolinium
  • DNA