title: Yeast RNase III as a key processing enzyme in small nucleolar RNAs metabolism.
abstract: The variety of biogenesis pathways for small nucleolar RNAs (snoRNAs) reflects the diversity of their genomic organization. We have searched for yeast snoRNAs which are affected by the depletion of the yeast ortholog of bacterial RNase III, Rnt1. In a yeast strain inactivated for RNT1, almost half of the snoRNAs tested are depleted with significant accumulation of monocistronic or polycistronic precursors. snoRNAs from both major families of snoRNAs (C/D and H/ACA) are affected by RNT1 disruption. In vitro, recombinant Rnt1 specifically cleaves pre-snoRNA precursors in the absence of other factors, generating intermediates which require the action of other enzymes for processing to the mature snoRNA. Most Rnt1 cleavage sites fall within potentially double-stranded regions closed by tetraloops with a novel consensus sequence AGNN. These results demonstrate that biogenesis of a large number of snoRNAs from the two major families of snoRNAs requires a common RNA endonuclease and a putative conserved structural motif.
authors.affiliation: Laboratoire du Métabolisme des ARN, URA1300 CNRS, Institut Pasteur, Département des Biotechnologies, 25 rue du Dr Roux, Paris Cedex 15, F-75724, France. guillom@pasteur.fr
authors.forename: G
authors.initials: G
authors.lastname: Chanfreau
authors.forename: P
authors.initials: P
authors.lastname: Legrain
authors.forename: A
authors.initials: A
authors.lastname: Jacquier
mesh_terms: D001483:Base Sequence; D001665:Binding Sites / Q000235:genetics; D002466:Cell Nucleolus / Q000378:metabolism; D016384:Consensus Sequence; D004722:Endoribonucleases / Q000235:genetics / Q000378:metabolism*; D005800:Genes, Fungal; D008969:Molecular Sequence Data; D008970:Molecular Weight; D009690:Nucleic Acid Conformation; D009694:Nucleic Acid Precursors / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D015345:Oligonucleotide Probes / Q000235:genetics; D012315:RNA Caps; D012323:RNA Processing, Post-Transcriptional; D012331:RNA, Fungal / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D012342:RNA, Small Nuclear / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D043244:Ribonuclease III; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins
chemical_list: D009694:Nucleic Acid Precursors; D015345:Oligonucleotide Probes; D012315:RNA Caps; D012331:RNA, Fungal; D012342:RNA, Small Nuclear; D011994:Recombinant Proteins; D029701:Saccharomyces cerevisiae Proteins; D004722:Endoribonucleases; C468367:RNT1 protein, S cerevisiae; D043244:Ribonuclease III