1. Biochemistry and Chemical Biology
  2. Structural Biology and Molecular Biophysics
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Mechanism of ribosome rescue by ArfA and RF2

  1. Gabriel Demo
  2. Egor Svidritskiy
  3. Rohini Madireddy
  4. Ruben Diaz-Avalos
  5. Timothy Grant
  6. Nikolaus Grigorieff
  7. Duncan Sousa
  8. Andrei A Korostelev  Is a corresponding author
  1. University of Massachusetts Medical School, United States
  2. Medicago, United States
  3. Janelia Research Campus, Howard Hughes Medical Institute, United States
  4. Florida State University, United States
Research Article
  • Cited 30
  • Views 2,335
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Cite this article as: eLife 2017;6:e23687 doi: 10.7554/eLife.23687

Abstract

ArfA rescues ribosomes stalled on truncated mRNAs by recruiting release factor RF2, which normally binds stop codons to catalyze peptide release. We report two 3.2-Å resolution cryo-EM structures – determined from a single sample – of the 70S ribosome with ArfA•RF2 in the A site. In both states, the ArfA C-terminus occupies the mRNA tunnel downstream of the A site. One state contains a compact inactive RF2 conformation. Ordering of the ArfA N-terminus in the second state rearranges RF2 into an extended conformation that docks the catalytic GGQ motif into the peptidyl-transferase center. Our work thus reveals the structural dynamics of ribosome rescue. The structures demonstrate how ArfA “senses” the vacant mRNA tunnel and activates RF2 to mediate peptide release without a stop codon, allowing stalled ribosomes to be recycled.

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The following data sets were generated

Article and author information

Author details

  1. Gabriel Demo

    RNA Therapeutics Institute, University of Massachusetts Medical School, Worcester, United States
    Competing interests
    No competing interests declared.
  2. Egor Svidritskiy

    RNA Therapeutics Institute, University of Massachusetts Medical School, Worcester, United States
    Competing interests
    No competing interests declared.
  3. Rohini Madireddy

    Medicago, Durham, United States
    Competing interests
    No competing interests declared.
  4. Ruben Diaz-Avalos

    Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
    Competing interests
    No competing interests declared.
  5. Timothy Grant

    Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
    Competing interests
    No competing interests declared.
  6. Nikolaus Grigorieff

    Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
    Competing interests
    Nikolaus Grigorieff, Reviewing editor, eLife.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0002-1506-909X
  7. Duncan Sousa

    Department of Biological Science, Florida State University, Tallahassee, United States
    Competing interests
    No competing interests declared.
  8. Andrei A Korostelev

    RNA Therapeutics Institute, University of Massachusetts Medical School, Worcester, United States
    For correspondence
    andrei.korostelev@umassmed.edu
    Competing interests
    No competing interests declared.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0003-1588-717X

Funding

National Institutes of Health (GM106105)

  • Andrei A Korostelev

National Institutes of Health (GM107465)

  • Andrei A Korostelev

The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.

Reviewing Editor

  1. Rachel Green, Johns Hopkins School of Medicine, United States

Publication history

  1. Received: November 27, 2016
  2. Accepted: March 14, 2017
  3. Accepted Manuscript published: March 16, 2017 (version 1)
  4. Version of Record published: April 3, 2017 (version 2)
  5. Version of Record updated: April 4, 2017 (version 3)

Copyright

© 2017, Demo 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.

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