Messenger RNAs (mRNAs) which lack a stop codon result in ribosomes stalled at the 3’ end of mRNA. Alternative ribosome-rescue factor B (ArfB) rescues by tRNA-peptide hydrolysis and thus releasing peptide. ArfB consists an N-terminal domain with GGQ motif required for hydrolysis, C-terminal acts as sensor empty mRNA entry channel, linker connecting domains. binds to ribosomal A site regardless l...

BACKGROUND The tmRNA quality control system recognizes stalled translation complexes and facilitates ribosome recycling in a process termed 'ribosome rescue'. During ribosome rescue, nascent chains are tagged with the tmRNA-encoded SsrA peptide, which targets tagged proteins for degradation. In Escherichia coli, tmRNA rescues ribosomes arrested on truncated messages, as well as ribosomes that a...

During protein synthesis in cells, translating ribosomes may encounter abnormal situations that lead to retention of immature peptidyl-tRNA on the ribosome due to failure of suitable termination processes. Bacterial cells handle such situations by employing three systems that rescue the stalled translation machinery. The transfer messenger RNA/small protein B (tmRNA/SmpB) system, also called th...

When the bacterial ribosome stalls on a truncated mRNA, transfer-messenger RNA (tmRNA) acts initially as a transfer RNA (tRNA) and then as a messenger RNA (mRNA) to rescue the ribosome and add a peptide tag to the nascent polypeptide that targets it for degradation. Ribosomal protein S1 binds tmRNA but its functional role in this process has remained elusive. In this report, we demonstrate that...

In eukaryotes, accurate protein synthesis relies on a family of translational GTPases that pair with specific decoding factors to decipher the mRNA code on ribosomes. We present structures of the mammalian ribosome engaged with decoding factor⋅GTPase complexes representing intermediates of translation elongation (aminoacyl-tRNA⋅eEF1A), termination (eRF1⋅eRF3), and ribosome rescue (Pelota⋅Hbs1l)...