title: Monomer-dimer equilibrium for the 5'-5' stacking of propeller-type parallel-stranded G-quadruplexes: NMR structural study.
abstract: 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.
authors.affiliation: School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore.
authors.forename: Ngoc Quang
authors.initials: NQ
authors.lastname: Do
authors.forename: Anh Tuân
authors.initials: AT
authors.lastname: Phan
mesh_terms: D002412:Cations / Q000737:chemistry*; D004247:DNA / Q000737:chemistry*; D054856:G-Quadruplexes; D006147:Guanine / Q000737:chemistry*; D046911:Macromolecular Substances; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D013696:Temperature
chemical_list: D002412:Cations; D046911:Macromolecular Substances; D006147:Guanine; D004247:DNA