U8 small nucleolar RNA
U8 small nucleolar RNA is the RNA component of a small RNA:protein complex which is required for biogenesis of mature large subunit ribosomal RNAs, 5.8S and 28S rRNAs.
More specifically, U8 is a non-coding RNA molecule which functions in the modification of other small nuclear RNAs. 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 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 and the D box. Most of the members of the box C/D family function in directing site-specific 2'-O-methylation of substrate RNAs.
U8 RNA genes have been identified in human, mouse, rat and the amphibian Xenopus laevis.
