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-Structure paper
Title | Cryo-EM structure of 90 small ribosomal subunit precursors in transition states. |
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Journal, issue, pages | Science, Vol. 369, Issue 6510, Page 1477-1481, Year 2020 |
Publish date | Sep 18, 2020 |
Authors | Yifei Du / Weidong An / Xing Zhu / Qi Sun / Jia Qi / Keqiong Ye / |
PubMed Abstract | The 90 preribosome is a large, early assembly intermediate of small ribosomal subunits that undergoes structural changes to give a pre-40 ribosome. Here, we gained insight into this transition by ...The 90 preribosome is a large, early assembly intermediate of small ribosomal subunits that undergoes structural changes to give a pre-40 ribosome. Here, we gained insight into this transition by determining cryo-electron microscopy structures of intermediates in the path from the 90 to the pre-40 The full transition is blocked by deletion of RNA helicase Dhr1. A series of structural snapshots revealed that the excised 5' external transcribed spacer (5' ETS) is degraded within 90, driving stepwise disassembly of assembly factors and ribosome maturation. The nuclear exosome, an RNA degradation machine, docks on the 90 through helicase Mtr4 and is primed to digest the 3' end of the 5' ETS. The structures resolved between 3.2- and 8.6-angstrom resolution reveal key intermediates and the critical role of 5' ETS degradation in 90 progression. |
External links | Science / PubMed:32943522 |
Methods | EM (single particle) |
Resolution | 3.2 - 8.6 Å |
Structure data | EMDB-0949, PDB-6lqp: EMDB-0950, PDB-6lqq: EMDB-0951, PDB-6lqr: EMDB-0952, PDB-6lqs: EMDB-0953, PDB-6lqt: |
Chemicals | ChemComp-ZN: ChemComp-GTP: ChemComp-MG: |
Source |
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Keywords | RIBOSOME / ribosome assembly / 90S to pre-40S transition / cryo-EM / Dhr1 |