title: Octaplex formation of d(GCGAAAGC) with the double A-quartet.
abstract: We reported that the sequence gcGA[X]1Agc adopts a specific structure to form several multiplexes. In the case of X=G, an octaplex formation occurs, in which the stacked double G-quartet stabilizes the architecture through potassium cation mediations. In the case of a mutant X=A, too, it has been found that the oligomers form an octaplex. The eight central A residues form a stacked double A-quartet, which is a first example of adenine associations. Several water molecules occupy the centre to stabilize the quartets, so that the octaplex seems to be swollen as compared with that of X=G. In any multiplex formations, the building block is a base-intercalated duplexes.
authors.affiliation: Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, Yokohama, Japan.
authors.forename: Kenta
authors.initials: K
authors.lastname: Mitomi
authors.forename: Jiro
authors.initials: J
authors.lastname: Kondo
authors.forename: Wataru
authors.initials: W
authors.lastname: Adachi
authors.forename: Shun-ichi
authors.initials: S
authors.lastname: Umeda
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Fujita
authors.forename: Tomoko
authors.initials: T
authors.lastname: Sunami
authors.forename: Akio
authors.initials: A
authors.lastname: Takénaka
mesh_terms: D000225:Adenine / Q000737:chemistry; D001483:Base Sequence; D004247:DNA / Q000737:chemistry*; D054856:G-Quadruplexes; D006147:Guanine / Q000737:chemistry; D018598:Minisatellite Repeats; D008958:Models, Molecular
chemical_list: D006147:Guanine; D004247:DNA; D000225:Adenine