title: Structure of the alpha-homo-DNA:RNA duplex and the function of twist and slide to catalogue nucleic acid duplexes.
abstract: High-resolution NMR studies of an alpha-homo-DNA:RNA duplex reveal the formation of a right-handed parallel-oriented helix. It differs significantly from a standard A- or B-type helix by a small twist value (26.2 degrees ), which leads to a helical pitch of 13.7 base pairs per helical turn, a negative inclination (-1.78 Angstrom) and a large x displacement (5.90 Angstrom). The rise (3.4 Angstrom) is similar to that found in B-DNA. The solution of this new helix structure has stimulated us to develop a mathematical and geometrical model based on slide and twist parameters to describe nucleic acid duplexes. All existing duplexes can be positioned within this landscape, which can be used to understand the helicalization process.
authors.affiliation: Laboratory of Medicinal Chemistry, Rega Institute for Medical Research, Minderbroedersstraat 10, 3000 Leuven, Belgium.
authors.forename: Koen
authors.initials: K
authors.lastname: Nauwelaerts
authors.forename: Eveline
authors.initials: E
authors.lastname: Lescrinier
authors.forename: Piet
authors.initials: P
authors.lastname: Herdewijn
mesh_terms: D009682:Magnetic Resonance Spectroscopy; D009690:Nucleic Acid Conformation; D009841:Oligonucleotides / Q000737:chemistry*; D012313:RNA / Q000737:chemistry*
chemical_list: D009841:Oligonucleotides; C448220:alpha-homo-DNA; D012313:RNA