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Visualizing tmRNA entry into a stalled ribosome.

Mikel Valle·Reynald Gillet·Sukhjit Kaur·Anke Henne·V Ramakrishnan·Joachim Frank
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Abstract

Bacterial ribosomes stalled on defective messenger RNAs (mRNAs) are rescued by tmRNA, an approximately 300-nucleotide-long molecule that functions as both transfer RNA (tRNA) and mRNA. Translation then switches from the defective message to a short open reading frame on tmRNA that tags the defective nascent peptide chain for degradation. However, the mechanism by which tmRNA can enter and move through the ribosome is unknown. We present a cryo-electron microscopy study at approximately 13 to 15 angstroms of the entry of tmRNA into the ribosome. The structure reveals how tmRNA could move through the ribosome despite its complicated topology and also suggests roles for proteins S1 and SmpB in the function of tmRNA.

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AlanineAnticodonBacterial ProteinsCodonCodon, TerminatorCryoelectron MicroscopyGuanosine TriphosphateImage Processing, Computer-AssistedModels, MolecularNucleic Acid ConformationOpen Reading FramesPeptide Elongation Factor TuProtein BiosynthesisPyridonesRNA, BacterialRNA, MessengerRNA, TransferRNA-Binding ProteinsRibosomal ProteinsRibosomesThermus thermophilusJournal ArticleResearch Support, Non-U.S. Gov'tResearch Support, U.S. Gov't, P.H.S.

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Mikel Valle, Reynald Gillet, Sukhjit Kaur, Anke Henne, V Ramakrishnan, Joachim Frank. 2003-04-04. Visualizing tmRNA entry into a stalled ribosome.. https://doi.org/10.1126/science.1081798

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