Structural basis of ribosomal peptide macrocyclization in plants

  1. Joel Haywood
  2. Jason W Schmidberger
  3. Amy M James
  4. Samuel G Nonis
  5. Kirill V Sukhoverkov
  6. Mikael Elias
  7. Charles S Bond
  8. Joshua S Mylne  Is a corresponding author
  1. The University of Western Australia, Australia
  2. University of Minnesota, United States

Abstract

Constrained, cyclic peptides encoded by plant genes represent a new generation of drug leads. Evolution has repeatedly recruited the Cys-protease asparaginyl endopeptidase (AEP) to perform their head-to-tail ligation. These macrocyclization reactions use the substrates amino terminus instead of water to deacylate, so a peptide bond is formed. How solvent-exposed plant AEPs macrocyclize is poorly understood. Here we present the crystal structure of an active plant AEP from the common sunflower, Helianthus annuus. The active site contained electron density for a tetrahedral intermediate with partial occupancy that predicted a binding mode for peptide macrocyclization. By substituting catalytic residues we could alter the ratio of cyclic to acyclic products. Moreover, we showed AEPs from other species lacking cyclic peptides can perform macrocyclization under favorable pH conditions. This structural characterization of AEP presents a logical framework for engineering superior enzymes that generate macrocyclic peptide drug leads.

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Article and author information

Author details

  1. Joel Haywood

    School of Molecular Sciences, The University of Western Australia, Perth, Australia
    Competing interests
    The authors declare that no competing interests exist.
  2. Jason W Schmidberger

    School of Molecular Sciences, The University of Western Australia, Perth, Australia
    Competing interests
    The authors declare that no competing interests exist.
  3. Amy M James

    School of Molecular Sciences, The University of Western Australia, Perth, Australia
    Competing interests
    The authors declare that no competing interests exist.
  4. Samuel G Nonis

    School of Molecular Sciences, The University of Western Australia, Perth, Australia
    Competing interests
    The authors declare that no competing interests exist.
  5. Kirill V Sukhoverkov

    School of Molecular Sciences, The University of Western Australia, Perth, Australia
    Competing interests
    The authors declare that no competing interests exist.
  6. Mikael Elias

    Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, St Paul, United States
    Competing interests
    The authors declare that no competing interests exist.
  7. Charles S Bond

    School of Molecular Sciences, The University of Western Australia, Perth, Australia
    Competing interests
    The authors declare that no competing interests exist.
  8. Joshua S Mylne

    School of Molecular Sciences, The University of Western Australia, Perth, Australia
    For correspondence
    joshua.mylne@uwa.edu.au
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0003-4957-6388

Funding

Australian Research Council (FT120100013)

  • Joshua S Mylne

Australian Research Council (DP160100107)

  • Joshua S Mylne

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

Reviewing Editor

  1. Charles S Craik, University of California, San Francisco, United States

Publication history

  1. Received: October 19, 2017
  2. Accepted: January 26, 2018
  3. Accepted Manuscript published: January 31, 2018 (version 1)
  4. Version of Record published: March 2, 2018 (version 2)

Copyright

© 2018, Haywood 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. Joel Haywood
  2. Jason W Schmidberger
  3. Amy M James
  4. Samuel G Nonis
  5. Kirill V Sukhoverkov
  6. Mikael Elias
  7. Charles S Bond
  8. Joshua S Mylne
(2018)
Structural basis of ribosomal peptide macrocyclization in plants
eLife 7:e32955.
https://doi.org/10.7554/eLife.32955

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