title: Structure of a stereoregular phosphorothioate DNA/RNA duplex.
abstract: In this work, we present the first NMR solution structure of a DNA/RNA hybrid containing stereoregular Rp-phosphorothioate modifications of all DNA backbone linkages. The complex of the enzymatically synthesized phosphorothioate DNA octamer (all-Rp)-d(GCGTCAGG) and its complementary RNA r(CCUGACGC) was found to adopt an overall conformation within the A-form family. Most helical parameters and the sugar puckers of the DNA strand assume values intermediate between A- and B-form. The close structural similarity with the unmodified DNA/RNA hybrid of the same sequence may explain why both the natural and the sulfur-substituted complex can be recognized and digested by ribonuclease H.
authors.affiliation: Institut für Organische Chemie und Biochemie, TU München, Garching, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Bachelin
authors.forename: G
authors.initials: G
authors.lastname: Hessler
authors.forename: G
authors.initials: G
authors.lastname: Kurz
authors.forename: J G
authors.initials: JG
authors.lastname: Hacia
authors.forename: P B
authors.initials: PB
authors.lastname: Dervan
authors.forename: H
authors.initials: H
authors.lastname: Kessler
mesh_terms: D001483:Base Sequence; D004247:DNA / Q000737:chemistry*; D008958:Models, Molecular; D019906:Nuclear Magnetic Resonance, Biomolecular / Q000379:methods; D009690:Nucleic Acid Conformation; D009692:Nucleic Acid Heteroduplexes / Q000737:chemistry*; D009838:Oligodeoxyribonucleotides / Q000737:chemistry*; D009843:Oligoribonucleotides / Q000737:chemistry*; D012313:RNA / Q000737:chemistry*; D016914:Ribonuclease H; D013873:Thionucleotides / Q000737:chemistry*
chemical_list: D009692:Nucleic Acid Heteroduplexes; D009838:Oligodeoxyribonucleotides; D009843:Oligoribonucleotides; D013873:Thionucleotides; D012313:RNA; D004247:DNA; D016914:Ribonuclease H