title: [Small nucleolar RNAs].
abstract: Small nucleolar RNAs (snoRNAs) are an abundant class of non-protein-coding RNAs. In association with proteins they perform two most frequent nucleotide modifications in rRNAs and some other cellular RNAs: 2'-O-ribose methylation and pseudouridylation. SnoRNAs also participate in pre-rRNA cleavage and telomerase functions. Most snoRNAs fall into two families, box C/D and H/ACA, distinguished by the presence of conserved sequence boxes. Although C/D and H/ACA snoRNP proteins contain homologous regions, the assembly of these RNPs significantly differ. In addition, snoRNAs include the RNA component of RNAses P and MRP. The structure and function of small RNPs from Cajal bodies (small organelles associated with nucleoli) similar to snoRNP are also discussed.
authors.forename: Iu A
authors.initials: IuA
authors.lastname: Makarova
authors.forename: D A
authors.initials: DA
authors.lastname: Kramerov
mesh_terms: D000818:Animals; D020541:Coiled Bodies / Q000235:genetics / Q000378:metabolism; D020537:RNA, Small Nucleolar / Q000145:classification* / Q000235:genetics / Q000378:metabolism*; D020718:Ribonucleoproteins, Small Nucleolar / Q000235:genetics / Q000378:metabolism
chemical_list: D020537:RNA, Small Nucleolar; D020718:Ribonucleoproteins, Small Nucleolar