title: Three-dimensional crystal structure of the A-tract DNA dodecamer d(CGCAAATTTGCG) complexed with the minor-groove-binding drug Hoechst 33258.
abstract: The molecular structure of the DNA A-tract dodecamer d(CGCAAATTTGCG) complexed with the drug Hoechst 33258 has been determined by X-ray diffraction analysis. The Hoechst molecule binds in the DNA minor groove covering the sequence AATTT of the central A-tract, with the piperazine group close to one of the GC regions. The drug molecule makes two three-centered hydrogen bonds from the nitrogen atoms of the benzimidazole rings to the N3 and O2 atoms of the DNA bases. Although a high propeller twist is observed in the A-tract, only one unsymmetrical three-centered hydrogen bond is present in the DNA major groove. The structure is compared with other minor-groove-binding drug complexes and the influence of these drugs on DNA A-tracts is discussed.
authors.affiliation: Departament de Biologia Molecular i Cel-lular, Centre d'Investigació i Desenvolupament-C.S.I.C., Barcelona, Spain.
authors.forename: M C
authors.initials: MC
authors.lastname: Vega
authors.forename: I
authors.initials: I
authors.lastname: García Sáez
authors.forename: J
authors.initials: J
authors.lastname: Aymamí
authors.forename: R
authors.initials: R
authors.lastname: Eritja
authors.forename: G A
authors.initials: GA
authors.lastname: Van der Marel
authors.forename: J H
authors.initials: JH
authors.lastname: Van Boom
authors.forename: A
authors.initials: A
authors.lastname: Rich
authors.forename: M
authors.initials: M
authors.lastname: Coll
mesh_terms: D001483:Base Sequence; D001665:Binding Sites; D006690:Bisbenzimidazole / Q000378:metabolism*; D018360:Crystallography, X-Ray; D004247:DNA / Q000737:chemistry / Q000378:metabolism*; D006860:Hydrogen Bonding; D007091:Image Processing, Computer-Assisted; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D009838:Oligodeoxyribonucleotides / Q000737:chemistry / Q000378:metabolism*
chemical_list: D009838:Oligodeoxyribonucleotides; D004247:DNA; D006690:Bisbenzimidazole