title: Selectivity in ligand recognition of G-quadruplex loops.
abstract: 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.
authors.affiliation: Cancer Research UK Biomolecular Structure Group, The School of Pharmacy, University of London, 29-39 Brunswick Square, London WC1N 1AX, UK.
authors.forename: Nancy H
authors.initials: NH
authors.lastname: Campbell
authors.forename: Manisha
authors.initials: M
authors.lastname: Patel
authors.forename: Amina B
authors.initials: AB
authors.lastname: Tofa
authors.forename: Ragina
authors.initials: R
authors.lastname: Ghosh
authors.forename: Gary N
authors.initials: GN
authors.lastname: Parkinson
authors.forename: Stephen
authors.initials: S
authors.lastname: Neidle
mesh_terms: D000166:Acridines / Q000737:chemistry; D018360:Crystallography, X-Ray; D054856:G-Quadruplexes; D008024:Ligands; D008958:Models, Molecular; D009690:Nucleic Acid Conformation; D013941:Thymine / Q000737:chemistry
chemical_list: D000166:Acridines; D008024:Ligands; D013941:Thymine