Effect of directional pulling on mechanical protein degradation by ATP-dependent proteolytic machines
Name
E6306.full.pdf
Size
1.11 MB
Format
Adobe PDF
Checksum (MD5)
21750d70759542897c8b564dbde37bbd
Author(s)
Olivares, Adrian O.
Kotamarthi, Hema Chandra
Stein, Benjamin Joseph
Sauer, Robert T.
Baker, Tania
Date Issued
July 2017
Journal
Proceedings of the National Academy of Sciences
Publisher
National Academy of Sciences (U.S.)
Citation
Olivares, Adrian O. et al. “Effect of Directional Pulling on Mechanical Protein Degradation by ATP-Dependent Proteolytic Machines.” Proceedings of the National Academy of Sciences 114, 31 (July 2017): E6306–E6313 © 2017 National Academy of Sciences
Version
Final published version
Abstract
AAA+ proteases and remodeling machines couple hydrolysis of ATP to mechanical unfolding and translocation of proteins following recognition of sequence tags called degrons. Here, we use single-molecule optical trapping to determine the mechanochemistry of two AAA+ proteases, Escherichia coli ClpXP and ClpAP, as they unfold and translocate substrates containing multiple copies of the titin[superscript I27] domain during degradation initiated from the N terminus. Previous studies characterized degradation of related substrates with C-terminal degrons. We find that ClpXP and ClpAP unfold the wild-type titin I27 domain and a destabilized variant far more rapidly when pulling from the N terminus, whereas translocation speed is reduced only modestly in the N-to-C direction. These measurements establish the role of directionality in mechanical protein degradation, show that degron placement can change whether unfolding or translocation is rate limiting, and establish that one or a few power strokes are sufficient to unfold some protein domains. Keywords:protein degradation; AAA+ proteases; directional unfolding; AAA+ motors
MIT Department
Massachusetts Institute of Technology. Department of Biology
Terms of Use
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.
Persistent DSpace Link
DOI of Published Version
https://doi.org/10.1073/PNAS.1707794114
