title: Sugar-Edge Interactions in a DNA-RNA G-Quadruplex: Evidence of Sequential C-H⋅⋅⋅O Hydrogen Bonds Contributing to RNA Quadruplex Folding.
abstract: DNA G-quadruplexes were systematically modified by single riboguanosine (rG) substitutions at anti-dG positions. Circular dichroism and NMR experiments confirmed the conservation of the native quadruplex topology for most of the DNA-RNA hybrid structures. Changes in the C8 NMR chemical shift of guanosines following rG substitution at their 3'-side within the quadruplex core strongly suggest the presence of C8-H⋅⋅⋅O hydrogen-bonding interactions with the O2' position of the C2'-endo ribonucleotide. A geometric analysis of reported high-resolution structures indicates that such interactions are a more general feature in RNA quadruplexes and may contribute to the observed preference for parallel topologies.
authors.affiliation: Institut für Biochemie, Ernst-Moritz-Arndt-Universität Greifswald, Felix-Hausdorff-Strasse 4, 17487, Greifswald, Germany.
authors.forename: Jonathan
authors.initials: J
authors.lastname: Dickerhoff
authors.affiliation: Institut für Biochemie, Ernst-Moritz-Arndt-Universität Greifswald, Felix-Hausdorff-Strasse 4, 17487, Greifswald, Germany.
authors.forename: Bettina
authors.initials: B
authors.lastname: Appel
authors.affiliation: Institut für Biochemie, Ernst-Moritz-Arndt-Universität Greifswald, Felix-Hausdorff-Strasse 4, 17487, Greifswald, Germany.
authors.forename: Sabine
authors.identifier: 0000-0002-8385-7274
authors.initials: S
authors.lastname: Müller
authors.affiliation: Institut für Biochemie, Ernst-Moritz-Arndt-Universität Greifswald, Felix-Hausdorff-Strasse 4, 17487, Greifswald, Germany.
authors.forename: Klaus
authors.identifier: 0000-0002-2736-6606
authors.initials: K
authors.lastname: Weisz
mesh_terms: D004247:DNA / Q000737:chemistry*; D054856:G-Quadruplexes; D006860:Hydrogen Bonding; D019906:Nuclear Magnetic Resonance, Biomolecular; D011789:Quantum Theory; D012313:RNA / Q000737:chemistry*; D059370:RNA Folding; D000073893:Sugars / Q000737:chemistry*
chemical_list: D000073893:Sugars; D012313:RNA; D004247:DNA
keywords: DNA-RNA hybrids; G-quadruplexes; NMR spectroscopy; hydrogen bonds