Fibrillarin (rRNA 2'-O-methyltransferase fibrillarin) is a component of a nucleolar small nuclear ribonucleoprotein (SnRNP) [ PUBMED:2026646 PUBMED:8493104 ]. It is a S-adenosyl-L-methionine-dependent methyltransferase that has the ability to … expand

Fibrillarin (rRNA 2'-O-methyltransferase fibrillarin) is a component of a nucleolar small nuclear ribonucleoprotein (SnRNP) [ PUBMED:2026646 PUBMED:8493104 ]. It is a S-adenosyl-L-methionine-dependent methyltransferase that has the ability to methylate both RNAs and proteins. Site specificity is provided by a guide RNA that base pairs with the substrate and methylation occurs at a characteristic distance from the sequence involved in base pairing with the guide RNA [ PUBMED:24352239 PUBMED:30540930 PUBMED:32017898 PUBMED:2686980 PUBMED:1825809 ]. Fibrillarin is associated with U3, U8 and U13 small nuclear RNAs in mammals [ PUBMED:2026646 ] and is similar to the yeast NOP1 protein [ PUBMED:2686980 ]. It has awell conserved sequence of around 320 amino acids, and contains 3 domains, an N-terminal Gly/Arg-richregion; a central domain resembling other RNA-binding proteins and containing an RNP-2-like consensussequence; and a C-terminal α-helical domain. An evolutionarily related pre-rRNA processing protein,which lacks the Gly/Arg-rich domain, has been found in various archaebacteria.