title: Molecular structure of the B-DNA dodecamer d(CGCAAATTTGCG)2. An examination of propeller twist and minor-groove water structure at 2.2 A resolution.
abstract: The crystal structure of the dodecanucleotide duplex d(CGCAAATTTGCG)2 has been solved to 2.2 A resolution and refined to an R-factor of 18.1% with the inclusion of 71 water molecules. The structure shows propeller twists of up to -20 degrees for the A.T base-pairs, although there is probably only one (weak) three-centre hydrogen bond in the six base-pair AT narrow minor-groove region. An extensive ribbon of hydration has been located in this groove that has features distinctive from the classic "spine of hydration". Solvation around phosphate groups is described, with several instances of water molecules bridging between phosphates.
authors.affiliation: Cancer Research Campaign Biomolecular Structure Unit, Institute of Cancer Research, Sutton, Surrey, U.K.
authors.forename: K J
authors.initials: KJ
authors.lastname: Edwards
authors.forename: D G
authors.initials: DG
authors.lastname: Brown
authors.forename: N
authors.initials: N
authors.lastname: Spink
authors.forename: J V
authors.initials: JV
authors.lastname: Skelly
authors.forename: S
authors.initials: S
authors.lastname: Neidle
mesh_terms: D001482:Base Composition; D001483:Base Sequence; D003460:Crystallization; D004247:DNA / Q000737:chemistry*; D006860:Hydrogen Bonding; D008958:Models, Molecular; D008969:Molecular Sequence Data; D015394:Molecular Structure; D009690:Nucleic Acid Conformation; D009838:Oligodeoxyribonucleotides / Q000737:chemistry*; D014867:Water / Q000737:chemistry; D014961:X-Ray Diffraction
chemical_list: D009838:Oligodeoxyribonucleotides; D014867:Water; D004247:DNA