Bao, ChenLoerch, SarahLing, ClarenceKorostelev, Andrei A.Grigorieff, NikolausErmolenko, Dmitri N.2022-08-232022-08-232020-05-192020-06-05<p>Bao C, Loerch S, Ling C, Korostelev AA, Grigorieff N, Ermolenko DN. mRNA stem-loops can pause the ribosome by hindering A-site tRNA binding. Elife. 2020 May 19;9:e55799. doi: 10.7554/eLife.55799. Epub ahead of print. PMID: 32427100. <a href="https://doi.org/10.7554/eLife.55799">Link to article on publisher's site</a></p>2050-084X (Linking)10.7554/eLife.5579932427100https://hdl.handle.net/20.500.14038/41462Although the elongating ribosome is an efficient helicase, certain mRNA stem-loop structures are known to impede ribosome movement along mRNA and stimulate programmed ribosome frameshifting via mechanisms that are not well understood. Using biochemical and single-molecule Forster resonance energy transfer (smFRET) experiments, we studied how frameshift-inducing stem-loops from E. coli dnaX mRNA and the gag-pol transcript of Human Immunodeficiency Virus (HIV) perturb translation elongation. We find that upon encountering the ribosome, the stem-loops strongly inhibit A-site tRNA binding and ribosome intersubunit rotation that accompanies translation elongation. Electron cryo-microscopy (cryo-EM) reveals that the HIV stem-loop docks into the A site of the ribosome. Our results suggest that mRNA stem-loops can transiently escape the ribosome helicase by binding to the A site. Thus, the stem-loops can modulate gene expression by sterically hindering tRNA binding and inhibiting translation elongation.en-US© 2020, Bao et al. This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.http://creativecommons.org/licenses/by/4.0/E. colichromosomesgene expressionmolecular biophysicsstructural biologyBiochemistryBiophysicsEnzymes and CoenzymesMolecular BiologyNucleic Acids, Nucleotides, and NucleosidesStructural BiologyVirusesmRNA stem-loops can pause the ribosome by hindering A-site tRNA bindingJournal Articlehttps://escholarship.umassmed.edu/cgi/viewcontent.cgi?article=5259&context=oapubs&unstamped=1https://escholarship.umassmed.edu/oapubs/424017992630oapubs/4240