Download MendeleyIntercalation of a Heterocyclic Ligand between Quartets in a G-Rich Tetrahelical Structure.
Kotar, A., Kocman, V., Plavec, J.(2020) Chemistry 26: 814-817
- PubMed: 31750579
- DOI: https://doi.org/10.1002/chem.201904923
- Primary Citation of Related Structures:
6SX3 - PubMed Abstract:
YES G-rich oligonucleotide VK2 folds into an AGCGA-quadruplex tetrahelical structure distinct and significantly different from G-quadruplexes, even though it contains four G 3 tracts. Herein, a bis-quinolinium ligand 360A with high affinity for G-quadruplex structures and selective telomerase inhibition is shown to strongly bind to VK2. Upon binding, 360A does not induce a conformational switch from VK2 to an expected G-quadruplex. In contrast, NMR structural study revealed formation of a well-defined VK2-360A complex with a 1:1 binding stoichiometry, in which 360A intercalates between GAGA- and GCGC-quartets in the central cavity of VK2. This is the first high-resolution structure of a G-quadruplex ligand intercalating into a G-rich tetrahelical fold. This unique mode of ligand binding into tetrahelical DNA architecture offers insights into the stabilization of an AGCGA-quadruplex by a heterocyclic ligand and provides guidelines for rational design of novel VK2 binding molecules with selectivity for different DNA secondary structures.
Organizational Affiliation:
National Institute of Chemistry, Hajdrihova 19, 1000, Ljubljana, Slovenia.
