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-Structure paper
タイトル | Structure of the Maturing 90S Pre-ribosome in Association with the RNA Exosome. |
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ジャーナル・号・ページ | Mol Cell, Vol. 81, Issue 2, Page 293-303.e4, Year 2021 |
掲載日 | 2021年1月21日 |
![]() | Benjamin Lau / Jingdong Cheng / Dirk Flemming / Giuseppe La Venuta / Otto Berninghausen / Roland Beckmann / Ed Hurt / ![]() |
PubMed 要旨 | Ribosome assembly is catalyzed by numerous trans-acting factors and coupled with irreversible pre-rRNA processing, driving the pathway toward mature ribosomal subunits. One decisive step early in ...Ribosome assembly is catalyzed by numerous trans-acting factors and coupled with irreversible pre-rRNA processing, driving the pathway toward mature ribosomal subunits. One decisive step early in this progression is removal of the 5' external transcribed spacer (5'-ETS), an RNA extension at the 18S rRNA that is integrated into the huge 90S pre-ribosome structure. Upon endo-nucleolytic cleavage at an internal site, A, the 5'-ETS is separated from the 18S rRNA and degraded. Here we present biochemical and cryo-electron microscopy analyses that depict the RNA exosome, a major 3'-5' exoribonuclease complex, in a super-complex with the 90S pre-ribosome. The exosome is docked to the 90S through its co-factor Mtr4 helicase, a processive RNA duplex-dismantling helicase, which strategically positions the exosome at the base of 5'-ETS helices H9-H9', which are dislodged in our 90S-exosome structures. These findings suggest a direct role of the exosome in structural remodeling of the 90S pre-ribosome to drive eukaryotic ribosome synthesis. |
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手法 | EM (単粒子) |
解像度 | 3.8 - 7.5 Å |
構造データ | EMDB-11807, PDB-7ajt: EMDB-11808, PDB-7aju: ![]() EMDB-11809: |
化合物 | ![]() ChemComp-ZN: ![]() ChemComp-MG: ![]() ChemComp-GTP: |
由来 |
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![]() | RIBOSOME / Ribosome biogenesis / Exosome / 90S pre-ribosome / A1 cleavage / Mtr4 |