U8 small nucleolar RNA

In molecular biology, U8 small nucleolar RNA (also known as SNORD118) is the RNA component of a small RNA:protein complex (the U8 snoRNP) which is required for biogenesis of mature large subunit ribosomal RNAs, 5.8S and 28S rRNAs.^[1][2]

U8 small nucleolar RNA
Predicted secondary structure and sequence conservation of U8
Identifiers
Symbol	U8
Alt. Symbols	CeN21; CeR-2
Rfam	RF00096
Other data
RNA type	Gene; snRNA; snoRNA; CD-box
Domain	Eukaryota
GO	GO:0005730 GO:0006396
SO	SO:0000593
PDB structures	PDBe

More specifically, U8 is a non-coding RNA (ncRNA) molecule which functions in the modification of other small nuclear RNAs (snRNAs). This type of modifying RNA is usually located in the nucleolus of the eukaryotic cell which is a major site of snRNA biogenesis. It is known as a small nucleolar RNA (snoRNA) and also often referred to as a guide RNA.

snoRNA U8 belongs to the C/D box class of snoRNAs which contain the conserved sequence motifs known as the C box (UGAUGA) and the D box (CUGA). Most of the members of the box C/D family function in directing site-specific 2'-O-methylation of substrate RNAs.^[3]

U8 RNA genes have been identified in human, mouse, rat and the amphibian Xenopus laevis.^[2]