Download MendeleyCryo-EM structure of 90 S small ribosomal subunit precursors in transition states.
Du, Y., An, W., Zhu, X., Sun, Q., Qi, J., Ye, K.(2020) Science 369: 1477-1481
- PubMed: 32943522 Search on PubMed
- DOI: https://doi.org/10.1126/science.aba9690
- Primary Citation Related Structures:
6LQP, 6LQQ, 6LQR, 6LQS, 6LQT, 6LQU, 6LQV - PubMed Abstract:
The 90 S preribosome is a large, early assembly intermediate of small ribosomal subunits that undergoes structural changes to give a pre-40 S ribosome. Here, we gained insight into this transition by determining cryo-electron microscopy structures of Saccharomyces cerevisiae intermediates in the path from the 90 S to the pre-40 S 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 S , driving stepwise disassembly of assembly factors and ribosome maturation. The nuclear exosome, an RNA degradation machine, docks on the 90 S 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 S progression.
- Key Laboratory of RNA Biology, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China.
Organizational Affiliation:
