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Electron Cryotomography of Bacterial Secretion Systems

Oikonomou, Catherine M. and Jensen, Grant J. (2019) Electron Cryotomography of Bacterial Secretion Systems. In: Protein Secretion in Bacteria. American Society for Microbiology , Washington, DC, pp. 1-12. ISBN 9781683670445.

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The envelope of bacterial cells consists of at least one‐and often two‐membranes, a cell wall, and possibly a surface layer. This envelope allows cells to differentiate themselves from their environment and handle the resulting osmotic pressure, but it also presents a significant obstacle. Anything a cell wishes to export, from a motility appendage to a plasmid, needs to be ushered across this barrier. To accomplish this, bacteria have evolved a battery of secretion systems. Secretion systems are often constructed from dozens of protein building blocks embedded in the cell's envelope. The size, complexity, and location of these machines make them a particular challenge for structural characterization. High‐resolution structure determination techniques such as X‐ray crystallography and transmission electron microscopy (TEM)‐based single‐particle reconstruction (SPR) require objects to be purified from their cellular environment. This is problematic for membrane‐associated proteins, which embed in the lipid bilayer by means of exposed hydrophobic patches. These patches can be protected during purification by adding detergents to the solvent, but often structural alterations still occur. Secretion systems are also unusually large targets and frequently lose peripheral or loosely‐associated components during purification. In addition, they often cross two membranes and are avidly linked to the cell wall.

Item Type:Book Section
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URLURL TypeDescription ItemJournal Article
Oikonomou, Catherine M.0000-0003-2312-4746
Jensen, Grant J.0000-0003-1556-4864
Additional Information:© 2019 American Society for Microbiology, Washington, DC. Published Online: 12 September 2019; Published Print: 01 September 2019.
Subject Keywords:bacterial secretion systems; electron cryotomography; flagellar motor; Legionella pneumophila; single‐particle reconstruction; type II secretion system; type III secretion system; type IV secretion system; type V secretion system
Record Number:CaltechAUTHORS:20210128-151238600
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Official Citation:Oikonomou, C.M. and Jensen, G.J. (2019). Electron Cryotomography of Bacterial Secretion Systems. In Protein Secretion in Bacteria (eds M. Sandkvist, E. Cascales and P.J. Christie).
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:107795
Deposited By: Tony Diaz
Deposited On:28 Jan 2021 23:24
Last Modified:16 Nov 2021 19:06

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