title: Site-specific pseudouridine formation in preribosomal RNA is guided by small nucleolar RNAs.
abstract: During the nucleolar maturation of eukaryotic ribosomal RNAs, many selected uridines are converted into pseudouridine by a thus far undefined mechanism. The nucleolus contains a large number of small RNAs (snoRNAs) that share two conserved sequence elements, box H and ACA. In this study, we demonstrate that site-specific pseudouridylation of rRNAs relies on short ribosomal signal sequences that are complementary to sequences in box H/ACA snoRNAs. Genetic depletion and reconstitution studies on yeast snR5 and snR36 snoRNAs demonstrate that box H/ACA snoRNAs function as guide RNAs in rRNA pseudouridylation. These results define a novel function for snoRNAs and further reinforce the idea that base pairing is the most common way to obtain specific substrate-"enzyme" interactions during rRNA maturation.
authors.affiliation: Laboratoire de Biologie Moléculaire du CNRS, Université Paul Sabatier, Toulouse, France.
authors.forename: P
authors.initials: P
authors.lastname: Ganot
authors.forename: M L
authors.initials: ML
authors.lastname: Bortolin
authors.forename: T
authors.initials: T
authors.lastname: Kiss
mesh_terms: D001482:Base Composition; D001483:Base Sequence; D008969:Molecular Sequence Data; D012322:RNA Precursors / Q000235:genetics*; D012342:RNA, Small Nuclear / Q000235:genetics*; D012441:Saccharomyces cerevisiae / Q000235:genetics*; D014529:Uridine / Q000235:genetics
chemical_list: D012322:RNA Precursors; D012342:RNA, Small Nuclear; D014529:Uridine