Monomer-dimer equilibrium for the 5′-5′ stacking of propeller-type parallel-stranded G-quadruplexes : NMR structural study

• Main Authors: Do, Ngoc Quang, Phan, Anh Tuân
• Other Authors: School of Biological Sciences
• Format: Article
• Language: English
• Published: 2013
• Online Access: https://hdl.handle.net/10356/99416; http://hdl.handle.net/10220/12935
• Institution: Nanyang Technological University

Guanine-rich sequence motifs, which contain tracts of three consecutive guanines connected by single non-guanine nucleotides, are abundant in the human genome and can form a robust G-quadruplex structure with high stability. Herein, by using NMR spectroscopy, we investigate the equilibrium between monomeric and 5′–5′ stacked dimeric propeller-type G-quadruplexes that are formed by DNA sequences containing GGGT motifs. We show that the monomer–dimer equilibrium depends on a number of parameters, including the DNA concentration, DNA flanking sequences, the concentration and type of cations, and the temperature. We report on the high-definition structure of a simple monomeric G-quadruplex containing three single-residue loops, which could serve as a reference for propeller-type G-quadruplex structures in solution.