Selectivity in ligand recognition of G-quadruplex loops

Biochemistry. 2009 Mar 3;48(8):1675-80. doi: 10.1021/bi802233v.


A series of disubstituted acridine ligands have been cocrystallized with a bimolecular DNA G-quadruplex. The ligands have a range of cyclic amino end groups of varying size. The crystal structures show that the diagonal loop in this quadruplex results in a large cavity for these groups, in contrast to the steric constraints imposed by propeller loops in human telomeric quadruplexes. We conclude that the nature of the loop has a significant influence on ligand selectivity for particular quadruplex folds.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acridines / chemistry
  • Crystallography, X-Ray
  • G-Quadruplexes*
  • Ligands
  • Models, Molecular
  • Nucleic Acid Conformation*
  • Thymine / chemistry


  • Acridines
  • Ligands
  • Thymine