User:Htafer/SNORD17

SNORD17 (also known as HBI-43) 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.

HBI-43 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.

This snoRNA is the human orthologue of mouse HBI-43. HBI-43 is predicted to guide 2'O-ribose methylation of 28s ribosomal RNA (rRNA) at position U3797. This residue (U3797) is also predicted to be pseudouridylated (the uridine residue is converted to pseudouridine) by the H/ACA box snoRNA ACA48.

All member of the HBI-43 family are exceptionally long for a C/D box snoRNA, ranging from 187 nt in Tetraodon to 256 nt in Spermophilus. Representative are reported in mammals , gnathostomes as well as in C. elegans In Eutheria, SNORD17 is located in an intron of SNX5. The second copy in the human genome is found in an intron of the adjacent OVOL2 gene. In T. belaneri, E. caballus, and S. araneus the annotated SNX5 gene is located downstream of SNORD17. Most likely, this is caused by incomplete gene models rather than a relocation of SNORD17. In Monodelphis, a second copy is located in CSRP2BP. In earlier gnathostomes, including the shark C. milii, however, SNORD17 is associated within dyskerin (DKC1), a key component of box H/ACA snoRNPs.