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Updated: Jan 2, 2026
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Examining Proteasome Assembly with Recombinant Archaeal Proteasomes and Nondenaturing PAGE: The Case for a Combined Approach
Published on: December 17, 2016
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Understanding the 26S proteasome molecular machine from a structural and conformational dynamics perspective
Eric R Greene1, Ken C Dong2, Andreas Martin2
1Department of Molecular Cell Biology, University of California Berkeley, Berkeley, CA 94720, USA; California Institute for Quantitative Biosciences, University of California Berkeley, Berkeley, CA 94720, USA.
Current Opinion in Structural Biology
|November 30, 2019
Summary
The 26S proteasome, a key cellular machine, degrades proteins via ATP hydrolysis. Recent studies reveal its structural mechanisms and conformational changes driving substrate degradation and ubiquitin removal.
Area of Science:
- Molecular Biology
- Cell Biology
- Structural Biology
Background:
- The 26S proteasome is crucial for protein homeostasis in eukaryotic cells.
- It mediates the ubiquitin-dependent degradation of damaged and regulatory proteins.
Purpose of the Study:
- To summarize recent advances in understanding the 26S proteasome's degradation mechanisms.
- To highlight the role of structural features and conformational changes in proteasome function.
Main Methods:
- Cryo-electron microscopy (cryo-EM) and cryo-electron tomography (cryo-ET) for structural insights.
- Biochemical and biophysical studies to analyze degradation steps and kinetics.
- In situ cellular studies to observe proteasome localization and interactions.
Main Results:
- New cryo-EM structures captured ATP-hydrolysis-driven substrate translocation.
- Biochemical studies detailed substrate selection and degradation commitment via conformational changes.
- Ubiquitin removal was shown to be mechanically coupled to degradation.
- Cryo-ET provided in-cell views of proteasome activity and interactions.
Conclusions:
- Structural and dynamic studies have significantly advanced our mechanistic understanding of the 26S proteasome.
- Conformational transitions are central to the multi-step substrate degradation process.
- The proteasome's structure enables efficient and regulated protein clearance within the cell.
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