6LQQ

Cryo-EM structure of 90S small subunit preribosomes in transition states (State B)

This is a non-PDB format compatible entry.

Summary for 6LQQ

• Entry DOI: 10.2210/pdb6lqq/pdb
• Related: 6LQP 6LQR 6LQS 6LQT 6LQU 6LQV
• EMDB information: 0949 0950 0951 0952 0953 0954 0955
• Descriptor: U3 snoRNA, 40S ribosomal protein S9-A, 40S ribosomal protein S11-A, ... (69 entities in total)
• Functional Keywords: ribosome assembly, 90s to pre-40s transition, cryo-em, dhr1, ribosome
• Biological source: Saccharomyces cerevisiae S288C (Baker's yeast); More
• Total number of polymer chains: 70
• Total formula weight: 4869931.82

Authors

Du, Y.,Ye, K. (deposition date: 2020-01-14, release date: 2020-09-16, Last modification date: 2024-03-27)

Primary citation

Du, Y.,An, W.,Zhu, X.,Sun, Q.,Qi, J.,Ye, K.
Cryo-EM structure of 90 S small ribosomal subunit precursors in transition states.
Science, 369:1477-1481, 2020

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 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.

PubMed: 32943522
DOI: 10.1126/science.aba9690

Experimental method

ELECTRON MICROSCOPY (4.1 Å)