| U20 | |||||||
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| snoid : SR0000281 | ||||||
| Length : 80 | ||||||
| Abstract : Homo sapiens C/D box snoRNA U20. This snoRNA was originally characterized in an intron of the human nucleolin gene by Nicoloso et al. (1994). U20 was postulated to guide the 2'O-ribose methylation of 18S rRNA U1804 by Kiss-Laszlo et al. (1996). Cavaillé et al. (1996) showed that U20 mutants in which the natural 18S rRNA complementarity was substituted by a complementarity to an 18S or 28S rRNA region devoid of 5'O-ribose methylation could efficiently guide that modification at the predicted site. U20, the C/D box snoRNA U82 and the H/ACA box snoRNA U23 share the same host gene (nucleolin). In vertebrates, U20 generally resides in the penultimate intron of the NCL gene. In zebrafish, a highly mutated copy resides in an upstream intron (see alignment), but no functional U20 snoRNA sequence could be found. The length of the 18S rRNA anti-sense sequence appears to have increased during evolution (Maden, 1986; Hedges et al., 1990; Quezada et al., 2006). Also note that U20 in fishes is devoid of D’ and C’ boxes. | ||||||
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| GenBank accession number : Z34290 | ||||||
| Host gene : NCL (nucleolin) | ||||||
| Click here to see the position on the UCSC Genome Browser | ||||||
| Target RNA : 18S rRNA U1804 | ||||||
| References : - Kiss-Laszlo, Z., Henry, Y., Bachellerie, J. P., Caizergues-Ferrer, M., and Kiss, T. (1996). Site-specific ribose methylation of preribosomal RNA: a novel function for small nucleolar RNAs. Cell, 85, 1077-1088. - Nicoloso, M., Caizergues-Ferrer, M., Michot, B., Azum, M. C., and Bachellerie, J. P. (1994). U20, a novel small nucleolar RNA, is encoded in an intron of the nucleolin gene in mammals. Mol Cell Biol, 14, 5766-5776. - Cavaille, J., Nicoloso, M., and Bachellerie, J. P. (1996). Targeted ribose methylation of RNA in vivo directed by tailored antisense RNA guides. Nature, 383, 732-735. | ||||||
| Sequence : | ||||||
| snoRNABase - http://www-snorna.biotoul.fr/ | |||||||