U17a  also known as E1
HUGO Gene Nomenclature Committee
HGNC Approved SymbolHGNC Approved Name
SNORA73Asmall nucleolar RNA, H/ACA box 73A
snoid : SR0000003
Length : 207
Abstract : Homo sapiens U17a/E1 snoRNA. This H/ACA box snoRNA was cloned from human cells by Ruff et al. (1993) and Kiss and Filipowicz (1993). Two isoforms of human U17 are encoded within the first (U17a) and second (U17b) introns of the non-coding U17HG gene (Pelczar and Filipowicz, 1998). Contrary to other H/ACA box snoRNAs, the 3'-terminal stem-loop (nts 135-207) of U17 is sufficient for assembly with the four core proteins of H/ACA snoRNPs, hGAR1, dyskerin, hNHP2 and hNOP10 (Dragon, Pogacic and Filipowicz, 2000). U17 is an evolutionarily conserved snoRNA that is also present in fission (S. pombe) and budding (S. cerevisiae) yeasts and the unicellular protozoan T. thermophila (Atzorn et al. 2004). Upon depletion of E1 RNA by anti-sens oligonucleotides in frog oocytes, 20S pre-rRNA was made, but 18S rRNA did not accumulate, suggesting that E1 snoRNA is involved in rRNA processing at the 5' end of 18S RNA (site 1) (Mishra and Eliceiri, 1997). Similarly, the yeast S. cerevisiae equivalent of U17, called snR30, is required for the nucleolytic processing of 18S rRNA. Consistent with this, psoralen cross-linking experiments found mammalian U17 to interact with primary rRNA transcripts (Rimoldi et al. 1993). Most likely, U17 functions as an RNA chaperone that safeguards the correct folding of 18S rRNA during pre-rRNA processing.
GenBank accession number : L16791
Host gene : U17HG
Click here to see the position on the UCSC Genome Browser
Target RNA : unknown
References :
- Ruff, E. A., Rimoldi, O. J., Raghu, B., and Eliceiri, G. L. (1993). Three small nucleolar RNAs of unique nucleotide sequences. Proc Natl Acad Sci U S A 90, 635-638
- Rimoldi, O. J., Raghu, B., Nag, M. K., and Eliceiri, G. L. (1993). Three new small nucleolar RNAs that are psoralen cross-linked in vivo to unique regions of pre-rRNA. Mol Cell Biol 13, 4382-4390.
- Atzorn, V., Fragapane, P., and Kiss, T. (2004). U17/snR30 is a ubiquitous snoRNA with two conserved sequence motifs essential for 18S rRNA production. Mol Cell Biol 24, 1769-1778.
- Kiss, T., and Filipowicz, W. (1993). Small nucleolar RNAs encoded by introns of the human cell cycle regulatory gene RCC1. Embo J, 12, 2913-2920.
- Pelczar, P., and Filipowicz, W. (1998). The host gene for intronic U17 small nucleolar RNAs in mammals has no protein-coding potential and is a member of the 5'-terminal oligopyrimidine gene family. Mol Cell Biol, 18, 4509-4518.
- Atzorn, V., Henry, Y. and Kiss, T. (2004) Production of 18S rRNA requires a novel type of base-pairing interaction with the U17/snR30 box H/ACA snoRNA. (submitted)
- Mishra, R. K., and Eliceiri, G. L. (1997). Three small nucleolar RNAs that are involved in ribosomal RNA precursor processing. Proc Natl Acad Sci U S A, 94, 4972-4977.
- Dragon, F., Pogacic, V., and Filipowicz, W. (2000). In vitro assembly of human H/ACA small nucleolar RNPs reveals unique features of U17 and telomerase RNAs. Mol Cell Biol, 20, 3037-3048.
Sequence :
snoRNABase - http://www-snorna.biotoul.fr/