Premium
Structural Studies Reveal Enantiospecific Recognition of a DNA G‐Quadruplex by a Ruthenium Polypyridyl Complex
Author(s) -
McQuaid Kane,
Abell Holly,
Gurung Sarah P.,
Allan David R.,
Winter Graeme,
Sorensen Thomas,
Cardin David J.,
Brazier John A.,
Cardin Christine J.,
Hall James P.
Publication year - 2019
Publication title -
angewandte chemie
Language(s) - English
Resource type - Journals
eISSN - 1521-3757
pISSN - 0044-8249
DOI - 10.1002/ange.201814502
Subject(s) - antiparallel (mathematics) , chemistry , isostructural , stereochemistry , g quadruplex , ruthenium , duplex (building) , dna , circular dichroism , crystallography , enantiomer , guanosine , luminescence , crystal structure , materials science , biochemistry , physics , quantum mechanics , magnetic field , catalysis , optoelectronics
By using X‐ray crystallography, we show that the complexes Λ/Δ‐[Ru(TAP) 2 (11‐CN‐dppz)] 2+ (TAP=1,4,5,8‐tetraazaphenanthrene, dppz=dipyridophenazine) bind DNA G‐quadruplex in an enantiospecific manner that parallels the specificity of these complexes with duplex DNA. The Λ complex crystallises with the normally parallel stranded d(TAGGGTTA) tetraplex to give the first such antiparallel strand assembly in which syn ‐guanosine is adjacent to the complex at the 5′ end of the quadruplex core. SRCD measurements confirm that the same conformational switch occurs in solution. The Δ enantiomer, by contrast, is present in the structure but stacked at the ends of the assembly. In addition, we report the structure of Λ‐[Ru(phen) 2 (11‐CN‐dppz)] 2+ bound to d(TCGGCGCCGA), a duplex‐forming sequence, and use both structural models to provide insight into the motif‐specific luminescence response of the isostructural phen analogue enantiomers.