Diversity and Similarity of Termination and Ribosome Rescue in Bacterial, Mitochondrial, and Cytoplasmic Translation

Biochemistry (Mosc). 2021 Sep;86(9):1107-1121. doi: 10.1134/S0006297921090066.


When a ribosome encounters the stop codon of an mRNA, it terminates translation, releases the newly made protein, and is recycled to initiate translation on a new mRNA. Termination is a highly dynamic process in which release factors (RF1 and RF2 in bacteria; eRF1•eRF3•GTP in eukaryotes) coordinate peptide release with large-scale molecular rearrangements of the ribosome. Ribosomes stalled on aberrant mRNAs are rescued and recycled by diverse bacterial, mitochondrial, or cytoplasmic quality control mechanisms. These are catalyzed by rescue factors with peptidyl-tRNA hydrolase activity (bacterial ArfA•RF2 and ArfB, mitochondrial ICT1 and mtRF-R, and cytoplasmic Vms1), that are distinct from each other and from release factors. Nevertheless, recent structural studies demonstrate a remarkable similarity between translation termination and ribosome rescue mechanisms. This review describes how these pathways rely on inherent ribosome dynamics, emphasizing the active role of the ribosome in all translation steps.

Keywords: rescue; ribosome; termination; translation.

Publication types

  • Review

MeSH terms

  • Bacteria / metabolism*
  • Bacterial Proteins / genetics
  • Bacterial Proteins / metabolism
  • Carboxylic Ester Hydrolases / metabolism
  • Cytoplasm / metabolism*
  • Mitochondria / metabolism*
  • Peptide Chain Termination, Translational
  • Protein Biosynthesis
  • RNA-Binding Proteins / genetics
  • RNA-Binding Proteins / metabolism
  • Ribosomal Proteins / genetics
  • Ribosomal Proteins / metabolism
  • Ribosomes / metabolism*


  • Bacterial Proteins
  • RNA-Binding Proteins
  • Ribosomal Proteins
  • Carboxylic Ester Hydrolases
  • aminoacyl-tRNA hydrolase