title: A network of heterogeneous hydrogen bonds in GNRA tetraloops.
abstract: RNA hairpin loops containing a GNRA consensus sequence are the most frequently occurring hairpins in a variety of prokaryotic and eukaryotic RNAs. These tetraloops play important functional roles in RNA folding, in RNA-RNA tertiary interactions and as protein binding sites. Homo and heteronuclear NMR spectroscopy have been used to determine the structures of the most abundant members of the GNRA tetraloop family: the GAGA, GCAA and GAAA loops closed by a C-G base pair. Analysis of the structures of these three hairpin loops reveals a network of heterogeneous hydrogen bonds. The loops contain a G-A base pair, a G base-phosphate hydrogen bond and several 2' OH-base hydrogen bonds. These intramolecular interactions and the extensive base stacking in the loop help explain the high thermodynamic stability and give insight into the diverse biological roles of the GNRA RNA hairpins.
authors.affiliation: Department of Chemistry and Biochemistry, University of Colorado at Boulder, 80309-0215, USA.
authors.forename: F M
authors.initials: FM
authors.lastname: Jucker
authors.forename: H A
authors.initials: HA
authors.lastname: Heus
authors.forename: P F
authors.initials: PF
authors.lastname: Yip
authors.forename: E H
authors.initials: EH
authors.lastname: Moors
authors.forename: A
authors.initials: A
authors.lastname: Pardi
mesh_terms: D001482:Base Composition; D001483:Base Sequence; D001665:Binding Sites; D006860:Hydrogen Bonding; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D008969:Molecular Sequence Data; D015394:Molecular Structure; D009690:Nucleic Acid Conformation; D009691:Nucleic Acid Denaturation; D012313:RNA / Q000737:chemistry* / Q000235:genetics; D013816:Thermodynamics
chemical_list: D012313:RNA