From Wikipedia, the free encyclopedia
| small Cajal body-specific RNA 17 |
 |
| Type: |
Gene; snRNA; guide; scaRNA; |
| 2° structure: |
Published;PubMed |
| Seed alignment: |
Moxon SJ |
| Avg length: |
141.8 nucleotides |
| Avg identity: |
81% |
|
scaRNAs are a specific class of small nuclear RNAs which localise to the Cajal bodies and guide the modification of RNA polymerase II transcribed spliceosomal RNAs U1, U2, U4, U5 and U12 [1]. The complete human U12-22/U4-8 scaRNA is composed of two tandem C/D box domains (termed U12-22 and U4-8). The 5' and 3' C/D domains are predicted to guide the 2'O-ribose methylation of residue U22 in U12 (RF00007) and residue C8 in U4 (RF00015) snRNAs respectively [1]. This family only includes only the 5' C/D box domain (U12-22) as the 3' C/D box is represented by RF00283. The 3' C/D domain (U4-8) was also cloned previously by Darzacq [2] and called U91. Both the doublet (U12-22/U4-8) and singlet (U4-8) forms of this snRNA have been purified from Hela cells [1]. The doublet form U12-22/U4-8 has been shown to localise to the nucleoplasm and is proposed to reside in the Cajal bodies whereas the U4-8 single domain appears to accumulate in the nucleolus [1]. In humans the genomic location of U12-88/U4-8 is intergenic and the purified transcript has been shown to possess a methylated guanosine cap suggesting it is independently transcribed by RNA pol II [1].
[edit] References
- [1] Tycowski, KT; Aab A, Steitz JA (2004). "Guide RNAs with 5' Caps and Novel Box C/D snoRNA-like Domains for Modification of snRNAs in Metazoa". Curr Biol 14: 1985–1995. doi:10.1016/j.cub.2004.11.003. PMID 15556860.
- [2] Darzacq, X; Jady BE, Verheggen C, Kiss AM, Bertrand E, Kiss T (2002). "Cajal body-specific small nuclear RNAs: a novel class of 2'-O-methylation and pseudouridylation guide RNAs". EMBO J. 21: 2746–2756. doi:10.1093/emboj/21.11.2746. PMID 12032087.
- [3] Lestrade, L; Weber MJ (2006). "snoRNA-LBME-db, a comprehensive database of human H/ACA and C/D box snoRNAs". Nucleic Acids Res. 34: D158–D162. doi:10.1093/nar/gkj002. PMID 16381836.
[edit] External links
