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-Structure paper
Title | Structure of a pre-catalytic spliceosome. |
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Journal, issue, pages | Nature, Vol. 546, Issue 7660, Page 617-621, Year 2017 |
Publish date | Jun 29, 2017 |
Authors | Clemens Plaschka / Pei-Chun Lin / Kiyoshi Nagai / |
PubMed Abstract | Intron removal requires assembly of the spliceosome on precursor mRNA (pre-mRNA) and extensive remodelling to form the spliceosome's catalytic centre. Here we report the cryo-electron microscopy ...Intron removal requires assembly of the spliceosome on precursor mRNA (pre-mRNA) and extensive remodelling to form the spliceosome's 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 stem-pre-mRNA and Brr2-U4 small nuclear RNA interactions. These results provide important insights into the events leading to active site formation. |
External links | Nature / PubMed:28530653 / PubMed Central |
Methods | EM (single particle) |
Resolution | 3.6 - 17.2 Å |
Structure data | EMDB-3682: EMDB-3683: Structure of a pre-catalytic spliceosome (B2 map) EMDB-3684: EMDB-3685: EMDB-3686: EMDB-3687: EMDB-3688: |
Chemicals | ChemComp-GTP: ChemComp-ZN: |
Source |
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Keywords | SPLICING / Spliceosome / Ribonucleoprotein |