Discovery and characterization of a novel family of prokaryotic nanocompartments involved in sulfur metabolism
- University of California, Berkeley, United States
- University of Toronto, Canada
- Lawrence Berkeley National Laboratory, United States
Abstract
Prokaryotic nanocompartments, also known as encapsulins, are a recently discovered proteinaceous organelle-like compartments in prokaryotes that compartmentalize cargo enzymes. While initial studies have begun to elucidate the structure and physiological roles of encapsulins, bioinformatic evidence suggests that a great diversity of encapsulin nanocompartments remains unexplored. Here, we describe a novel encapsulin in the freshwater cyanobacterium Synechococcus elongatus PCC 7942. This nanocompartment is upregulated upon sulfate starvation and encapsulates a cysteine desulfurase enzyme via an N-terminal targeting sequence. Using cryo-electron microscopy, we have determined the structure of the nanocompartment complex to 2.2 Å resolution. Lastly, biochemical characterization of the complex demonstrated that the activity of the cysteine desulfurase is enhanced upon encapsulation. Taken together, our discovery, structural analysis, and enzymatic characterization of this prokaryotic nanocompartment provide a foundation for future studies seeking to understand the physiological role of this encapsulin in various bacteria.
Data availability
Cryo-EM maps of holo and apo-SrpI have been deposited at the EM Data Resource with accession codes EMD-22094 and EMD-22095 respectively. The refined coordinate model has been deposited at the Protein Data Bank (PDB) with accession code 6X8M and 6X8T.
Article and author information
Author details
Funding
U.S. Department of Energy (Grant DE-SC00016240 (to D.F.S))
- Robert J Nichols
- Naiya R Phillips
- Luke M Oltrogge
- David F Savage
National Science Foundation (GRFP-1106400)
- Benjamin LaFrance
Howard Hughes Medical Institute
- Eva Nogales
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Copyright
© 2021, Nichols 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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Discovery and characterization of a novel family of prokaryotic nanocompartments involved in sulfur metabolism
eLife 10:e59288.
https://doi.org/10.7554/eLife.59288
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