Adenine-Driven Structural Switch from a Two- to Three-Quartet DNA G-Quadruplex.Lenarcic Zivkovic, M., Rozman, J., Plavec, J.
(2018) Angew. Chem. Int. Ed. Engl. 57: 15395-15399
- PubMed: 30222243
- DOI: 10.1002/anie.201809328
- PubMed Abstract:
A G-rich sequence found in the regulatory region of the RANKL gene, which is associated with homeostasis of bone metabolism, folds into a two-quartet basket-type G-quadruplex stabilized by A⋅G⋅A and G⋅G⋅G base-triads. Perusal of local structural feat ...
A G-rich sequence found in the regulatory region of the RANKL gene, which is associated with homeostasis of bone metabolism, folds into a two-quartet basket-type G-quadruplex stabilized by A⋅G⋅A and G⋅G⋅G base-triads. Perusal of local structural features together with G/A-to-T modifications uncovered the critical role of A5 for the formation of a distinct antiparallel two-quartet topology and not the three-quartet topology that would be expected based on the sequence with four GGG-tracts alone. The structural changes induced by the A5-to-T5 modification include a switch in orientation and relative positions of G-strands that together with anti to syn reorientation of G12 provide insights into the complexity of the interactions that influence the folding of G-rich DNA. Understanding the impact of loop residues on the stability and formation of G-quadruplexes advances our knowledge and ability to predict structures adopted by G-rich sequences, which are involved in regulatory mechanisms in the cell, and may also facilitate drug design.
Slovenian NMR Centre, National Institute of Chemistry, Hajdrihova 9, Ljubljana, Slovenia.,EN- FIST Centre of Excellence, Trg OF 13, Ljubljana, Slovenia.,Faculty of Chemistry and Chemical Technology, University of Ljubljana, Večna pot 113, Ljubljana, Slovenia.