EMD-13958
Structure of the SmrB-bound E. coli disome - collided 70S ribosome
EMD-13958
Single-particle5.7 Å
Deposition: 09/12/2021
Map released: 22/06/2022
Last modified: 16/10/2024
Sample Organism:
Escherichia coli,
Vibrio alginolyticus
Sample: collided ribosome of the SmrB-bound disome structure
Fitted models: 7qgr (Avg. Q-score: 0.112)
Deposition Authors: Kratzat H , Buschauer R , Berninghausen O , Beckmann R
Sample: collided ribosome of the SmrB-bound disome structure
Fitted models: 7qgr (Avg. Q-score: 0.112)
Deposition Authors: Kratzat H , Buschauer R , Berninghausen O , Beckmann R
Ribosome collisions induce mRNA cleavage and ribosome rescue in bacteria.
Saito K,
Kratzat H ,
Campbell A,
Buschauer R ,
Burroughs AM ,
Berninghausen O ,
Aravind L,
Green R ,
Beckmann R ,
Buskirk AR
(2022) Nature , 603 , 503 - 508
(2022) Nature , 603 , 503 - 508
Abstract:
Ribosome rescue pathways recycle stalled ribosomes and target problematic mRNAs and aborted proteins for degradation1,2. In bacteria, it remains unclear how rescue pathways distinguish ribosomes stalled in the middle of a transcript from actively translating ribosomes3-6. 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 mRNAs3) 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.
Ribosome rescue pathways recycle stalled ribosomes and target problematic mRNAs and aborted proteins for degradation1,2. In bacteria, it remains unclear how rescue pathways distinguish ribosomes stalled in the middle of a transcript from actively translating ribosomes3-6. 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 mRNAs3) 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.