SNORD64 (also known as HBII-13) is a non-coding RNA (ncRNA) molecule which functions in the biogenesis (modification) of other small nuclear RNAs (snRNAs). This type of modifiying RNA is 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.
SNORD64 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.
snoRNA HBII-13 is expressed mainly in the tissues of brain, but is also in the lungs, the kidneys and muscle; however HBII-13 has no identified target RNA. The HBII-13 gene is located in a 460 kb intron of the large paternally-expressed transcription unit (SNURF-SNRNP-UBE3A AS) along with several other snoRNAs HBII-436, HBII-437, HBII-438A/B and the clusters of HBII-85, HBII-52. This host gene is an antisense transcript to maternally expressed UBE3A gene.
^Runte, Maren; Hüttenhofer, Alexander; Gross, Stephanie; Kiefmann, Martin; Horsthemke, Bernhard; Buiting, Karin (2001). "The IC-SNURF-SNRPN transcript serves as a host for multiple small nucleolar RNA species and as an antisense RNA for UBE3A". Human Molecular Genetics10 (23): 2687–2700. doi:10.1093/hmg/10.23.2687. PMID11726556.edit