Delta chirality ruthenium ‘light-switch’ complexes can bind in the minor groove of DNA with five different binding modes

DOI: 10.1093/nar/gkw753

Authors: James P. Hall (University of Reading; Diamond Light Source) , Paraic M. Keane (University of Reading) , Hanna Beer (University of Reading) , Katrin Buchner (University of Reading) , Graeme Winter (Diamond Light Source) , Thomas Sorensen (Diamond Light Source) , David J. Cardin (University of Reading) , John A. Brazier (University of Reading) , Christine J. Cardin (University of Reading)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Nucleic Acids Research

State: Published (Approved)
Published: September 2016
Diamond Proposal Number(s): 8420

Abstract: [Ru(phen)2(dppz)]2+ has been studied since the 1990s due to its ‘light-switch’ properties. It can be used as a luminescent DNA probe, with emission switched on through DNA binding. The luminescence observed is dependent on the solvent accessibility of the pyrazine nitrogen atoms, and therefore is sensitive to changes in both binding site of the cation and chromophore orientation. The compound is also chiral, and there are distinct differences between the enantiomers in terms of the emission behaviour when bound to a variety of DNA sequences. Whilst a number of binary DNA-complex X-ray crystal structures are available, most include the Λ enantiomer and there is very little structural information about binding of the Δ enantiomer. Here, we present the first X-ray crystal structure of a Δ enantiomer bound to well-matched DNA, in the absence of the other, Λ enantiomer. We show how the binding site observed here can be related to a more general pattern of motifs in the crystallographic literature and propose that the Δ enantiomer can bind with five different binding modes, offering a new hypothesis for the interpretation of solution data.

Subject Areas: Biology and Bio-materials


Instruments: I02-Macromolecular Crystallography

Added On: 14/11/2016 12:16

Discipline Tags:

Structural biology Life Sciences & Biotech

Technical Tags:

Diffraction Macromolecular Crystallography (MX)