7QGN

Structure of the SmrB-bound E. coli disome - stalled 70S ribosome

This is a non-PDB format compatible entry.

Summary for 7QGN

• Entry DOI: 10.2210/pdb7qgn/pdb
• EMDB information: 13952 13955 13956
• Descriptor: A-site tRNA, 50S ribosomal protein L6, 50S ribosomal protein L9, ... (61 entities in total)
• Functional Keywords: ribosome rescue, disome, ribosome collision, stalling, no-go complex, nuclease, smrb, ribosome
• Biological source: Escherichia coli; More
• Total number of polymer chains: 58
• Total formula weight: 2264812.14

Authors

Kratzat, H.,Buschauer, R.,Berninghausen, O.,Beckmann, R. (deposition date: 2021-12-09, release date: 2022-04-27, Last modification date: 2024-10-16)

Primary citation

Saito, K.,Kratzat, H.,Campbell, A.,Buschauer, R.,Burroughs, A.M.,Berninghausen, O.,Aravind, L.,Green, R.,Beckmann, R.,Buskirk, A.R.
Ribosome collisions induce mRNA cleavage and ribosome rescue in bacteria.
Nature, 603:503-508, 2022

PubMed Abstract: Ribosome rescue pathways recycle stalled ribosomes and target problematic mRNAs and aborted proteins for degradation. In bacteria, it remains unclear how rescue pathways distinguish ribosomes stalled in the middle of a transcript from actively translating ribosomes. Here, using a genetic screen in Escherichia coli, we discovered a new rescue factor that has endonuclease activity. SmrB cleaves mRNAs upstream of stalled ribosomes, allowing the ribosome rescue factor tmRNA (which acts on truncated mRNAs) to rescue upstream ribosomes. SmrB is recruited to ribosomes and is activated by collisions. Cryo-electron microscopy structures of collided disomes from E. coli and Bacillus subtilis show distinct and conserved arrangements of individual ribosomes and the composite SmrB-binding site. These findings reveal the underlying mechanisms by which ribosome collisions trigger ribosome rescue in bacteria.

PubMed: 35264790
DOI: 10.1038/s41586-022-04416-7

Experimental method

ELECTRON MICROSCOPY (3.37 Å)