title: The contribution of pseudouridine to stabilities and structure of RNAs.
abstract: Thermodynamic data are reported revealing that pseudouridine (Ψ) can stabilize RNA duplexes when replacing U and forming Ψ-A, Ψ-G, Ψ-U and Ψ-C pairs. Stabilization is dependent on type of base pair, position of Ψ within the RNA duplex, and type and orientation of adjacent Watson-Crick pairs. NMR spectra demonstrate that for internal Ψ-A, Ψ-G and Ψ-U pairs, the N3 imino proton is hydrogen bonded to the opposite strand nucleotide and the N1 imino proton may also be hydrogen bonded. CD spectra show that general A-helix structure is preserved, but there is some shifting of peaks and changing of intensities. Ψ has two hydrogen donors (N1 and N3 imino protons) and two hydrogen bond acceptors because the glycosidic bond is C-C rather than C-N as in uridine. This greater structural potential may allow Ψ to behave as a kind of structurally driven universal base because it can enhance stability relative to U when paired with A, G, U or C inside a double helix. These structural and thermodynamic properties may contribute to the biological functions of Ψ.
authors.affiliation: Institute of Bioorganic Chemistry, Polish Academy of Sciences, 61-704 Poznan, Noskowskiego 12/14, Poland and Department of Chemistry, University of Rochester, Rochester, NY 14627, USA.
authors.forename: Elzbieta
authors.initials: E
authors.lastname: Kierzek
authors.forename: Magdalena
authors.initials: M
authors.lastname: Malgowska
authors.forename: Jolanta
authors.initials: J
authors.lastname: Lisowiec
authors.forename: Douglas H
authors.initials: DH
authors.lastname: Turner
authors.forename: Zofia
authors.initials: Z
authors.lastname: Gdaniec
authors.forename: Ryszard
authors.initials: R
authors.lastname: Kierzek
mesh_terms: D020029:Base Pairing; D006860:Hydrogen Bonding; D011560:Pseudouridine / Q000737:chemistry*; D020871:RNA Stability; D012330:RNA, Double-Stranded / Q000737:chemistry*; D013816:Thermodynamics
chemical_list: D012330:RNA, Double-Stranded; D011560:Pseudouridine