title: RNA quadruplex containing G and A.
abstract: The CD study of r(GGAGGAA) has indicated that it forms a higher order structure upon either increase of the strand concentration or addition of K+. Gel electrophoresis showed that a high molecular weight species is formed in the presence of K+. The NMR study revealed a nearly 1:1 equilibrium of two kinds of higher order structures at the strand concentration of 2.1 mM and 100 mM Na+. This equilibrium shifted drastically upon addition of K+, and only one structure remained at 40 mM K+. It is suggested that the structure formed by r(GGAGGAA) in the presence of K+ is a new type of RNA quadruplex, where an A-quartet stabilized by mutual hydrogen bonding among the four adenine bases is sandwiched by conventional G-quartets.
authors.affiliation: Department of Bioengineering, Faculty of Engineering, Yokohama National University, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Katahira
authors.forename: K
authors.initials: K
authors.lastname: Moriyama
authors.forename: M
authors.initials: M
authors.lastname: Kanagawa
authors.forename: J
authors.initials: J
authors.lastname: Saeki
authors.forename: M H
authors.initials: MH
authors.lastname: Kim
authors.forename: M
authors.initials: M
authors.lastname: Nagaoka
authors.forename: M
authors.initials: M
authors.lastname: Ide
authors.forename: S
authors.initials: S
authors.lastname: Uesugi
authors.forename: T
authors.initials: T
authors.lastname: Kono
mesh_terms: D000225:Adenine / Q000737:chemistry; D001483:Base Sequence; D002942:Circular Dichroism; D006147:Guanine / Q000737:chemistry; D006860:Hydrogen Bonding; D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure; D009690:Nucleic Acid Conformation; D009843:Oligoribonucleotides / Q000138:chemical synthesis / Q000737:chemistry; D011188:Potassium; D012313:RNA / Q000737:chemistry*
chemical_list: D009843:Oligoribonucleotides; D006147:Guanine; D012313:RNA; D000225:Adenine; D011188:Potassium