View source for 8qcb


==CryoEM structure of a S. Cerevisiae Ski2387 complex in the open state==
<StructureSection load='8qcb' size='340' side='right'caption='[[8qcb]], [[Resolution|resolution]] 2.80&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[8qcb]] is a 5 chain structure with sequence from [https://en.wikipedia.org/wiki/Saccharomyces_cerevisiae Saccharomyces cerevisiae]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=8QCB OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=8QCB FirstGlance]. <br>
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">Electron Microscopy, [[Resolution|Resolution]] 2.8&#8491;</td></tr>
<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=8qcb FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=8qcb OCA], [https://pdbe.org/8qcb PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=8qcb RCSB], [https://www.ebi.ac.uk/pdbsum/8qcb PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=8qcb ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/SKI2_YEAST SKI2_YEAST] RNA helicase component of the SKI complex involved in 3'-mRNA degradation pathway. Represses dsRNA virus propagation by specifically blocking translation of viral mRNAs, perhaps recognizing the absence of CAP or poly(A). Essential for cell growth only in the presence of M1 replicon.<ref>PMID:8321235</ref> <ref>PMID:363683</ref> <ref>PMID:6371496</ref> <ref>PMID:7739552</ref> <ref>PMID:7739557</ref> <ref>PMID:9482746</ref> <ref>PMID:10611222</ref> <ref>PMID:10744028</ref> <ref>PMID:10922069</ref> <ref>PMID:11532933</ref> <ref>PMID:11720286</ref> <ref>PMID:12769863</ref> <ref>PMID:14671320</ref> 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
The Ski2-Ski3-Ski8 (Ski238) helicase complex directs cytoplasmic mRNAs toward the nucleolytic exosome complex for degradation. In yeast, the interaction between Ski238 and exosome requires the adaptor protein Ski7. We determined different cryo-EM structures of the Ski238 complex depicting the transition from a rigid autoinhibited closed conformation to a flexible active open conformation in which the Ski2 helicase module has detached from the rest of Ski238. The open conformation favors the interaction of the Ski3 subunit with exosome-bound Ski7, leading to the recruitment of the exosome. In the Ski238-Ski7-exosome holocomplex, the Ski2 helicase module binds the exosome cap, enabling the RNA to traverse from the helicase through the internal exosome channel to the Rrp44 exoribonuclease. Our study pinpoints how conformational changes within the Ski238 complex regulate exosome recruitment for RNA degradation. We also reveal the remarkable conservation of helicase-exosome RNA channeling mechanisms throughout eukaryotic nuclear and cytoplasmic exosome complexes.

Concerted structural rearrangements enable RNA channeling into the cytoplasmic Ski238-Ski7-exosome assembly.,Keidel A, Kogel A, Reichelt P, Kowalinski E, Schafer IB, Conti E Mol Cell. 2023 Oct 19:S1097-2765(23)00803-1. doi: 10.1016/j.molcel.2023.09.037. PMID:37879335<ref>PMID:37879335</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 8qcb" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Saccharomyces cerevisiae]]
[[Category: Conti E]]
[[Category: Keidel A]]
[[Category: Koegel A]]
[[Category: Kowalinski E]]
[[Category: Reichelt P]]
[[Category: Schaefer IB]]