title: Complicated water orientations in the minor groove of the B-DNA decamer d(CCATTAATGG)2 observed by neutron diffraction measurements.
abstract: It has long been suspected that the structure and function of a DNA duplex can be strongly dependent on its degree of hydration. By neutron diffraction experiments, we have succeeded in determining most of the hydrogen (H) and deuterium (D) atomic positions in the decameric d(CCATTAATGG)2 duplex. Moreover, the D positions in 27 D2O molecules have been determined. In particular, the complex water network in the minor groove has been observed in detail. By a combined structural analysis using 2.0 A resolution X-ray and 3.0 A resolution neutron data, it is clear that the spine of hydration is built up, not only by a simple hexagonal hydration pattern (as reported in earlier X-ray studies), but also by many other water bridges hydrogen-bonded to the DNA strands. The complexity of the hydration pattern in the minor groove is derived from an extraordinary variety of orientations displayed by the water molecules.
authors.affiliation: Neutron Science Research Center, Japan Atomic Energy Research Institute 2-4 Shirakatashirane, Tokai, Ibaraki 319-1195, Japan.
authors.forename: Shigeki
authors.initials: S
authors.lastname: Arai
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Chatake
authors.forename: Takashi
authors.initials: T
authors.lastname: Ohhara
authors.forename: Kazuo
authors.initials: K
authors.lastname: Kurihara
authors.forename: Ichiro
authors.initials: I
authors.lastname: Tanaka
authors.forename: Nobuhiro
authors.initials: N
authors.lastname: Suzuki
authors.forename: Zui
authors.initials: Z
authors.lastname: Fujimoto
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Mizuno
authors.forename: Nobuo
authors.initials: N
authors.lastname: Niimura
mesh_terms: D001483:Base Sequence; D004247:DNA / Q000737:chemistry*; D003903:Deuterium / Q000737:chemistry; D006859:Hydrogen / Q000737:chemistry; D006860:Hydrogen Bonding; D033363:Neutron Diffraction; D009690:Nucleic Acid Conformation; D009838:Oligodeoxyribonucleotides / Q000737:chemistry*; D014867:Water / Q000737:chemistry*
chemical_list: D009838:Oligodeoxyribonucleotides; C501050:d(CCATTAATGG)2 B-DNA decamer; D014867:Water; D006859:Hydrogen; D004247:DNA; D003903:Deuterium