title: Elements essential for accumulation and function of small nucleolar RNAs directing site-specific pseudouridylation of ribosomal RNAs.
abstract: During site-specific pseudouridylation of eukaryotic rRNAs, selection of correct substrate uridines for isomerization into pseudouridine is directed by small nucleolar RNAs (snoRNAs). The pseudouridylation guide snoRNAs share a common 'hairpin-hinge- hairpin-tail' secondary structure and two conserved sequence motifs, the H and ACA boxes, located in the single-stranded hinge and tail regions, respectively. In the 5'- and/or 3'-terminal hairpin, an internal loop structure, the pseudouridylation pocket, selects the target uridine through formation of base-pairing interactions with rRNAs. Here, essential elements for accumulation and function of rRNA pseudouridylation guide snoRNAs have been analysed by expressing various mutant yeast snR5, snR36 and human U65 snoRNAs in yeast cells. We demonstrate that the H and ACA boxes that are required for formation of the correct 5' and 3' ends of the snoRNA, respectively, are also essential for the pseudouridylation reaction directed by both the 5'- and 3'-terminal pseudouridylation pockets. Similarly, RNA helices flanking the two pseudouridylation pockets are equally essential for pseudouridylation reactions mediated by either the 5' or 3' hairpin structure, indicating that the two hairpin domains function in a highly co-operative manner. Finally, we demonstrate that by manipulating the rRNA recognition motifs of pseudouridylation guide snoRNAs, novel pseudouridylation sites can be generated in yeast rRNAs.
authors.affiliation: Laboratoire de Biologie Moléculaire Eucaryote du CNRS, 118 route de Narbonne, 31062 Toulouse, France.
authors.forename: M L
authors.initials: ML
authors.lastname: Bortolin
authors.forename: P
authors.initials: P
authors.lastname: Ganot
authors.forename: T
authors.initials: T
authors.lastname: Kiss
mesh_terms: D001483:Base Sequence; D001665:Binding Sites / Q000235:genetics; D015870:Gene Expression; D006801:Humans; D066298:In Vitro Techniques; D007438:Introns; D008969:Molecular Sequence Data; D009154:Mutation; D009690:Nucleic Acid Conformation; D010957:Plasmids / Q000235:genetics; D011560:Pseudouridine / Q000378:metabolism; D012313:RNA / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D012315:RNA Caps / Q000235:genetics / Q000378:metabolism; D012335:RNA, Ribosomal / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D012342:RNA, Small Nuclear / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism
chemical_list: D012315:RNA Caps; D012335:RNA, Ribosomal; D012342:RNA, Small Nuclear; C039919:RNA, recombinant; C065039:RNA, ribosomal, 25S; D011560:Pseudouridine; D012313:RNA