A complex IRES at the 5'-UTR of a viral mRNA assembles a functional 48S complex via an uAUG intermediate

  1. Ritam Neupane
  2. Vera P Pisareva
  3. Carlos F Rodriguez
  4. Andrey V Pisarev  Is a corresponding author
  5. Israel S Fernández  Is a corresponding author
  1. Columbia University, United States
  2. SUNY Downstate Medical Center, United States
  3. CNIO, Spain

Abstract

Taking control of the cellular apparatus for protein production is a requirement for virus progression. To ensure this control, diverse strategies of cellular mimicry and/or ribosome hijacking evolved. The initiation stage of translation is specially targeted as it involves multiple steps and the engagement of numerous initiation factors. The use of structured RNA sequences, called Internal Ribosomal Entry Sites (IRES) in viral RNAs is a widespread strategy for the exploitation of eukaryotic initiation. Using a combination of electron cryo-microscopy (cryo-EM) and reconstituted translation initiation assays with native components, we characterized how a novel IRES at the 5'-UTR of a viral RNA assembles a functional initiation complex via an uAUG intermediate. The IRES features a novel extended, multi-domain architecture, circling the 40S head. The structures and accompanying functional data, illustrate the importance of 5'-UTR regions in translation regulation and underline the relevance of the untapped diversity of viral IRESs.

Data availability

Atomic coordinates have been deposited in the PDB with accession numbers and 6W2S and 6W2T. CryoEM maps have been deposited at the EMDB with accession numbers EMDB 21529/21530

The following data sets were generated

Article and author information

Author details

  1. Ritam Neupane

    Department of Biochemistry and Molecular Biophysics, Columbia University, New York, United States
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0003-4787-279X
  2. Vera P Pisareva

    Department of Cell Biology, SUNY Downstate Medical Center, New York, United States
    Competing interests
    The authors declare that no competing interests exist.
  3. Carlos F Rodriguez

    Structural Biology Program, CNIO, Madrid, Spain
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0001-9166-0132
  4. Andrey V Pisarev

    Department of Cell Biology, SUNY Downstate Medical Center, New York, United States
    For correspondence
    andrey.pisarev@downstate.edu
    Competing interests
    The authors declare that no competing interests exist.
  5. Israel S Fernández

    Department of Biochemistry and Molecular Biophysics, Columbia University, New York, United States
    For correspondence
    isf2106@cumc.columbia.edu
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0001-7218-1603

Funding

Columbia University (Start package)

  • Israel S Fernández

National Institute of General Medical Sciences (GM097014)

  • Andrey V Pisarev

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

Copyright

© 2020, Neupane 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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  1. Ritam Neupane
  2. Vera P Pisareva
  3. Carlos F Rodriguez
  4. Andrey V Pisarev
  5. Israel S Fernández
(2020)
A complex IRES at the 5'-UTR of a viral mRNA assembles a functional 48S complex via an uAUG intermediate
eLife 9:e54575.
https://doi.org/10.7554/eLife.54575

Share this article

https://doi.org/10.7554/eLife.54575

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