title: A U-tetrad stabilizes human telomeric RNA G-quadruplex structure.
abstract: Telomeric repeat-containing RNA is a new noncoding RNA molecule recently discovered in mammalian cells. Here we report the structural features of human telomere RNA r(UAGGGU) in the presence of K(+) and Na(+). We demonstrated for the first time that a novel U-tetrad is formed at the 3' end of a parallel human telomeric RNA G-quadruplex. The U-tetrad dramatically stabilizes human telomeric RNA G-quadruplex structure, leading to an increase in melting temperature (T(m)) of 29 degrees C. The U-tetrad-stabilized telomeric RNA G-quadruplex structure adds considerably to our understanding of the diversity of RNA G-quadruplex architectures. It shows that the structure of base "quartets" is important in RNA assembly. The structural information will be invaluable for understanding the function of human telomere RNA.
authors.affiliation: Research Center for Advanced Science and Technology, The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8904, Japan. xuyan@mkomi.rcast.u-tokyo.ac.jp
authors.forename: Yan
authors.initials: Y
authors.lastname: Xu
authors.forename: Takumi
authors.initials: T
authors.lastname: Ishizuka
authors.forename: Takashi
authors.initials: T
authors.lastname: Kimura
authors.forename: Makoto
authors.initials: M
authors.lastname: Komiyama
mesh_terms: D054856:G-Quadruplexes; D006801:Humans; D011188:Potassium / Q000737:chemistry; D020871:RNA Stability; D022661:RNA, Untranslated / Q000737:chemistry*; D012964:Sodium / Q000737:chemistry; D016615:Telomere / Q000737:chemistry* / Q000235:genetics
chemical_list: D022661:RNA, Untranslated; D012964:Sodium; D011188:Potassium