title: Determination of the backbone torsion angle epsilon in nucleic acids.
abstract: The multiplet structure of cross peaks in double-quantum-filtered COSY NMR spectra is analysed for those resonances that include passive heteronuclear couplings. Interestingly, the cross peak involving the sugar-ring protons H2' and H3' in nucleic acids display an E. COSY-type appearance exclusively when the backbone torsion angle epsilon (C4'-C3'-O3'-P) adopts a gauche(-) conformation. This observation allows an unambiguous analysis of the conformation around epsilon, without the knowledge of 3JCP coupling constants.
authors.affiliation: Department of Physics, Ciba-Geigy AG, Basel, Switzerland.
authors.forename: M J
authors.initials: MJ
authors.lastname: Blommers
authors.forename: D
authors.initials: D
authors.lastname: Nanz
authors.forename: O
authors.initials: O
authors.lastname: Zerbe
mesh_terms: D001483:Base Sequence; D009682:Magnetic Resonance Spectroscopy; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation