Single-Molecule Protein Unfolding and Translocation by an ATP-Fueled Proteolytic Machine
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Baker_Single-molecule.pdf
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Author(s)
Aubin-Tam, Marie-Eve
Olivares, Adrian O.
Baker, Tania
Lang, Matthew J.
Olivares, Adrian O.
Sauer, Robert T.
Sauer, Robert T
Date Issued
April 2011
Journal
Cell
Publisher
Elsevier B.V.
Citation
Aubin-Tam, Marie-Eve, Adrian O. Olivares, Robert T. Sauer, Tania A. Baker, and Matthew J. Lang. “Single-Molecule Protein Unfolding and Translocation by an ATP-Fueled Proteolytic Machine.” Cell 145, no. 2 (April 2011): 257-267. © 2011 Elsevier Inc.
Version
Final published version
Abstract
All cells employ ATP-powered proteases for protein-quality control and regulation. In the ClpXP protease, ClpX is a AAA+ machine that recognizes specific protein substrates, unfolds these molecules, and then translocates the denatured polypeptide through a central pore and into ClpP for degradation. Here, we use optical-trapping nanometry to probe the mechanics of enzymatic unfolding and translocation of single molecules of a multidomain substrate. Our experiments demonstrate the capacity of ClpXP and ClpX to perform mechanical work under load, reveal very fast and highly cooperative unfolding of individual substrate domains, suggest a translocation step size of 5–8 amino acids, and support a power-stroke model of denaturation in which successful enzyme-mediated unfolding of stable domains requires coincidence between mechanical pulling by the enzyme and a transient stochastic reduction in protein stability. We anticipate that single-molecule studies of the mechanical properties of other AAA+ proteolytic machines will reveal many shared features with ClpXP.
MIT Department
Massachusetts Institute of Technology. Department of Biological Engineering
Massachusetts Institute of Technology. Department of Biology
Massachusetts Institute of Technology. Department of Mechanical Engineering
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Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use.
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DOI of Published Version
https://doi.org/10.1016/j.cell.2011.03.036
