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Structure of a pre-catalytic spliceosome
- Source :
- Nature. June 29, 2017, Vol. 546 Issue 7660, p617, 5 p.
- Publication Year :
- 2017
-
Abstract
- Intron removal requires assembly of the spliceosome on precursor mRNA (pre-mRNA) and extensive remodelling to form the spliceosomes catalytic centre. Here we report the cryo-electron microscopy structure of the yeast Saccharomyces cerevisiae pre-catalytic B complex spliceosome at near-atomic resolution. The mobile U2 small nuclear ribonucleoprotein particle (snRNP) associates with U4/U6.U5 tri-snRNP through the U2/U6 helix II and an interface between U4/U6 di-snRNP and the U2 snRNP SF3b-containing domain, which also transiently contacts the helicase Brr2. The 3 region of the U2 snRNP is flexibly attached to the SF3b-containing domain and protrudes over the concave surface of tri-snRNP, where the U1 snRNP may reside before its release from the pre-mRNA 5 splice site. The U6 ACAGAGA sequence forms a hairpin that weakly tethers the 5 splice site. The B complex proteins Prp38, Snu23 and Spp381 bind the Prp8 N-terminal domain and stabilize U6 ACAGAGA stempre-mRNA and Brr2U4 small nuclear RNA interactions. These results provide important insights into the events leading to active site formation.<br />Author(s): Clemens Plaschka (corresponding author) [1]; Pei-Chun Lin (corresponding author) [1]; Kiyoshi Nagai (corresponding author) [1] Splicing of pre-mRNA is an important step in eukaryotic gene expression, in which non-coding [...]
Details
- Language :
- English
- ISSN :
- 00280836
- Volume :
- 546
- Issue :
- 7660
- Database :
- Gale General OneFile
- Journal :
- Nature
- Publication Type :
- Academic Journal
- Accession number :
- edsgcl.497319654
- Full Text :
- https://doi.org/10.1038/nature22799