title: Structural study of the H/ACA snoRNP components Nop10p and the 3' hairpin of U65 snoRNA.
abstract: The H/ACA small nucleolar ribonucleoprotein (snoRNP) complexes guide the modification of uridine to pseudouridine at conserved sites in rRNA. The H/ACA snoRNPs each comprise a target-site-specific snoRNA and four core proteins, Nop10p, Nhp2p, Gar1p, and the pseudouridine synthase, Cbf5p, in yeast. The secondary structure of the H/ACA snoRNAs includes two hairpins that each contain a large internal loop (the pseudouridylation pocket), one or both of which are partially complementary to the target RNA(s). We have determined the solution structure of an RNA hairpin derived from the human U65 box H/ACA snoRNA including the pseudouridylation pocket and adjacent stems, providing the first three-dimensional structural information on these H/ACA snoRNAs. We have also determined the structure of Nop10p and investigated its interaction with RNA using NMR spectroscopy. Nop10p contains a structurally well-defined N-terminal region composed of a beta-hairpin, and the rest of the protein lacks a globular structure. Chemical shift mapping of the interaction of RNA constructs of U65 box H/ACA 3' hairpin with Nop10p shows that the beta-hairpin binds weakly but specifically to RNA. The unstructured region of Nop10p likely interacts with Cbf5p.
authors.affiliation: Department of Chemistry and Biochemistry, 607 Charles Young Drive East, P.O. Box 951569, University of California, Los Angeles, CA 90095-1569, USA.
authors.forename: May
authors.initials: M
authors.lastname: Khanna
authors.forename: Haihong
authors.initials: H
authors.lastname: Wu
authors.forename: Carina
authors.initials: C
authors.lastname: Johansson
authors.forename: Michèle
authors.initials: M
authors.lastname: Caizergues-Ferrer
authors.forename: Juli
authors.initials: J
authors.lastname: Feigon
mesh_terms: D000595:Amino Acid Sequence; D006801:Humans; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000737:chemistry* / Q000235:genetics*; D009690:Nucleic Acid Conformation; D017434:Protein Structure, Tertiary; D011560:Pseudouridine / Q000737:chemistry* / Q000378:metabolism; D016601:RNA-Binding Proteins / Q000737:chemistry* / Q000235:genetics*; D017411:Ribonucleoproteins, Small Nuclear / Q000737:chemistry* / Q000235:genetics; D020718:Ribonucleoproteins, Small Nucleolar / Q000737:chemistry*; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry* / Q000235:genetics*; D017385:Sequence Homology
chemical_list: C485802:GAR1 protein, human; C117016:NOP10 protein, S cerevisiae; D009687:Nuclear Proteins; D016601:RNA-Binding Proteins; D017411:Ribonucleoproteins, Small Nuclear; D020718:Ribonucleoproteins, Small Nucleolar; D029701:Saccharomyces cerevisiae Proteins; D011560:Pseudouridine