Abstract

Photosynthetic organisms have adapted to survive a myriad of extreme environments from the earth’s deserts to its poles, yet the proteins that carry out the light reactions of photosynthesis are highly conserved from the cyanobacteria to modern day crops. To investigate adaptations of the photosynthetic machinery in cyanobacteria to excessive light stress, we isolated a new strain of cyanobacteria, Cyanobacterium aponinum 0216, from the extreme light environment of the Sonoran Desert. Here we report the biochemical characterization and the 2.7 Å resolution structure of trimeric photosystem I from this high-light tolerant cyanobacterium. The structure shows a new conformation of the PsaL C-terminus that supports trimer formation of cyanobacterial photosystem Ipectroscopic analysis of this photosystem I revealed a decrease in far-red absorption, which is attributed to a decrease in the number of long wavelength chlorophylls. Using these findings, we constructed two chimeric PSIs in Synechocystis sp. PCC 6803 demonstrating how unique structural features in photosynthetic complexes can change spectroscopic properties, allowing organisms to thrive under different environmental stresses.

Data availability

The final model (PDBID 6VPV) and map (EMD-21320) were deposited in the Protein Databank and Electron Microscopy Database, respectively.C. aponinum genomic DNA was deposited in NCBI genebank under NCBI:txid2676140.

The following data sets were generated

Article and author information

Author details

  1. Zachary Dobson

    School of Molecular Sciences., Arizona State University, Tempe, United States
    Competing interests
    The authors declare that no competing interests exist.
  2. Safa Ahad

    Department of Chemistry, Purdue University, West Lafayette, United States
    Competing interests
    The authors declare that no competing interests exist.
  3. Jackson Vanlandingham

    School of Molecular Sciences., Arizona State University, Tempe, United States
    Competing interests
    The authors declare that no competing interests exist.
  4. Hila Toporik

    School of Molecular Sciences., Arizona State University, Tempe, United States
    Competing interests
    The authors declare that no competing interests exist.
  5. Natalie Vaughn

    School of Molecular Sciences., Arizona State University, Tempe, United States
    Competing interests
    The authors declare that no competing interests exist.
  6. Michael Vaughn

    School of Molecular Sciences., Arizona State University, Tempe, United States
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0001-9357-094X
  7. Dewight Williams

    John M. Cowley Center for High Resolution Electron Microscopy, Arizona State University, Tempe, United States
    Competing interests
    The authors declare that no competing interests exist.
  8. Michael Reppert

    Department of Chemistry, Purdue University, West Lafayette, United States
    Competing interests
    The authors declare that no competing interests exist.
  9. Petra Fromme

    John M. Cowley Center for High Resolution Electron Microscopy, Arizona State University, Tempe, United States
    Competing interests
    The authors declare that no competing interests exist.
  10. Yuval Mazor

    School of Molecular Sciences., Arizona State University, Tempe, United States
    For correspondence
    yuval.mazor@asu.edu
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0001-5072-0928

Funding

National Institute of Food and Agriculture (2020-67034-31742)

  • Zachary Dobson

Biodesign, Center of Applied Structural Discovery. (1)

  • Zachary Dobson

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

Reviewing Editor

  1. David M Kramer, Michigan State University, United States

Version history

  1. Received: February 13, 2021
  2. Accepted: August 25, 2021
  3. Accepted Manuscript published: August 26, 2021 (version 1)
  4. Version of Record published: September 9, 2021 (version 2)

Copyright

© 2021, Dobson 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. Zachary Dobson
  2. Safa Ahad
  3. Jackson Vanlandingham
  4. Hila Toporik
  5. Natalie Vaughn
  6. Michael Vaughn
  7. Dewight Williams
  8. Michael Reppert
  9. Petra Fromme
  10. Yuval Mazor
(2021)
The structure of photosystem I from a high-light tolerant Cyanobacteria
eLife 10:e67518.
https://doi.org/10.7554/eLife.67518

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https://doi.org/10.7554/eLife.67518

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