tmRNA to the rescue Structural motives for the salvage of stalled ribosomes

Research output: Contribution to journalDebate/Note/Editorial


During translation, mRNA molecules are incidentally damaged, leaving the ribosome unable to reach or recognize the stop codon and thus stalled with mRNA and a potentially harmful polypeptide product attached to tRNA in the ribosomal P-site. In bacteria, a process called trans-translation has evolved, where a protein-RNA complex (smpB-tmRNA) mimicks the role of aminoacyl charged tRNA in the ribosomal A-site. The ribosome then resumes protein synthesis guided by an mRNA-like portion of the tmRNA which ends with a stop codon and codes for a peptide sequence susceptible to proteolysis, thus allowing the bacteria to salvage stalled ribosomes and degrade ill-defined and potentially harmful protein products. In this article, we will recollect how structural studies have yielded a model for how the pre-translocation stages of trans-translation employing structural mimicry. We will also discuss possible models for


  • Martin Lindahl
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Biological Sciences


  • trans-translation, tmRNA, SmpB, cryo electron microscopy, single, particle, heterogeneity analysis
Original languageEnglish
Pages (from-to)577-581
JournalRNA Biology
Issue number5
Publication statusPublished - 2010
Publication categoryResearch