title: NMR scalar couplings across Watson-Crick base pair hydrogen bonds in DNA observed by transverse relaxation-optimized spectroscopy.
abstract: This paper describes the NMR observation of 15N---15N and 1H---15N scalar couplings across the hydrogen bonds in Watson-Crick base pairs in a DNA duplex, hJNN and hJHN. These couplings represent new parameters of interest for both structural studies of DNA and theoretical investigations into the nature of the hydrogen bonds. Two dimensional [15N,1H]-transverse relaxation-optimized spectroscopy (TROSY) with a 15N-labeled 14-mer DNA duplex was used to measure hJNN, which is in the range 6-7 Hz, and the two-dimensional hJNN-correlation-[15N,1H]-TROSY experiment was used to correlate the chemical shifts of pairs of hydrogen bond-related 15N spins and to observe, for the first time, hJHN scalar couplings, with values in the range 2-3.6 Hz. TROSY-based studies of scalar couplings across hydrogen bonds should be applicable for large molecular sizes, including protein-bound nucleic acids.
authors.affiliation: Institut für Molekularbiologie und Biophysik, Eidgenössische Technische Hochschule, Hönggerberg CH-8093 Zürich, Switzerland.
authors.forename: K
authors.initials: K
authors.lastname: Pervushin
authors.forename: A
authors.initials: A
authors.lastname: Ono
authors.forename: C
authors.initials: C
authors.lastname: Fernández
authors.forename: T
authors.initials: T
authors.lastname: Szyperski
authors.forename: M
authors.initials: M
authors.lastname: Kainosho
authors.forename: K
authors.initials: K
authors.lastname: Wüthrich
mesh_terms: D020029:Base Pairing; D001483:Base Sequence; D004247:DNA / Q000737:chemistry*; D006860:Hydrogen Bonding; D008956:Models, Chemical; D019906:Nuclear Magnetic Resonance, Biomolecular / Q000379:methods; D009690:Nucleic Acid Conformation; D009838:Oligodeoxyribonucleotides / Q000737:chemistry*
chemical_list: D009838:Oligodeoxyribonucleotides; D004247:DNA