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

Chemistry. 2012 Nov 12;18(46):14752-9. doi: 10.1002/chem.201103295. Epub 2012 Sep 27.

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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cations / chemistry*
  • DNA / chemistry*
  • G-Quadruplexes
  • Guanine / chemistry*
  • Macromolecular Substances
  • Magnetic Resonance Spectroscopy
  • Models, Molecular
  • Molecular Sequence Data
  • Nucleic Acid Conformation
  • Temperature

Substances

  • Cations
  • Macromolecular Substances
  • Guanine
  • DNA