Ribosome collisions induce mRNA cleavage and ribosome rescue in bacteria.

ABSTRACT: Ribosome rescue pathways recycle stalled ribosomes and target problematic mRNAs and aborted proteins for degradation^1,2. In bacteria, it remains unclear how rescue pathways distinguish ribosomes stalled in the middle of a transcript from actively translating ribosomes^3-6. 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

SUBMITTER: Saito K 

PROVIDER: S-EPMC8934283 | biostudies-literature | 2022 Mar

REPOSITORIES: biostudies-literature