Structural Basis for Ribosome Rescue in Bacteria

Publication date: Available online 16 June 2017
Source:Trends in Biochemical Sciences
Author(s): Paul Huter, Claudia Müller, Stefan Arenz, Bertrand Beckert, Daniel N. Wilson
Ribosomes that translate mRNAs lacking stop codons become stalled at the 3′ end of the mRNA. Recycling of these stalled ribosomes is essential for cell viability. In bacteria three ribosome rescue systems have been identified so far, with the most ubiquitous and best characterized being the trans-translation system mediated by transfer–messenger RNA (tmRNA) and small protein B (SmpB). The two additional rescue systems present in some bacteria employ alternative rescue factor (Arf) A and release factor (RF) 2 or ArfB. Recent structures have revealed how ArfA mediates ribosome rescue by recruiting the canonical termination factor RF2 to ribosomes stalled on truncated mRNAs. This now provides us with the opportunity to compare and contrast the available structures of all three bacterial ribosome rescue systems.



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