Biomaterial Database

[Small nucleolar RNAs]. 2007

Iu A Makarova, and D A Kramerov

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.

UI	MeSH Term	Description	Entries
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D020537	RNA, Small Nucleolar	Small nuclear RNAs that are involved in the processing of pre-ribosomal RNA in the nucleolus. Box C/D containing snoRNAs (U14, U15, U16, U20, U21 and U24-U63) direct site-specific methylation of various ribose moieties. Box H/ACA containing snoRNAs (E2, E3, U19, U23, and U64-U72) direct the conversion of specific uridines to pseudouridine. Site-specific cleavages resulting in the mature ribosomal RNAs are directed by snoRNAs U3, U8, U14, U22 and the snoRNA components of RNase MRP and RNase P.	Small Nucleolar RNA,snoRNA
D020541	Coiled Bodies	A distinct subnuclear domain enriched in splicesomal snRNPs (RIBONUCLEOPROTEINS, SMALL NUCLEAR) and p80-coilin.	Accessory Bodies of Cajal,Cajal Bodies,Cajal Accessory Bodies,Coiled Body
D020718	Ribonucleoproteins, Small Nucleolar	Nucleolar RNA-protein complexes that function in pre-ribosomal RNA processing.	Small Nucleolar Ribonucleoprotein,Small Nucleolar Ribonucleoproteins,snoRNP,Nucleolar Ribonucleoprotein, Small,Ribonucleoprotein, Small Nucleolar