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The Proteasome Structure

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The ubiquitin-proteasome pathway is a well-known mechanism utilized by eukaryotic cells to remove cytoplasmic proteins that are misfolded, damaged, or no longer needed. In this pathway, the protein that needs to be eliminated undergoes a process called ubiquitination, where a chain of ubiquitin molecules is attached to the 48th lysine residue of the target protein. This ubiquitin modification helps the proteasome distinguish between a target protein and a healthy protein.
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Related Experiment Video

Updated: Jul 12, 2026

X-Ray Crystallography to Study the Oligomeric State Transition of the Thermotoga maritima M42 Aminopeptidase TmPep1050

X-Ray Crystallography to Study the Oligomeric State Transition of the Thermotoga maritima M42 Aminopeptidase TmPep1050

Published on: May 13, 2020

Structural principles of intramembrane proteases.

¹Department of Pharmacology, Yale School of Medicine, 333 Cedar Street, New Haven, CT 06520, USA. ya.ha@yale.edu

Current Opinion in Structural Biology

|August 24, 2007

Summary

Intramembrane proteases cleave membrane proteins, crucial for cell signaling and growth factor activation. Recent structural studies reveal how these enzymes function within cell membranes.

Area of Science:

Biochemistry
Structural Biology
Molecular Biology

Background:

Intramembrane proteases are enzymes embedded within cell membranes, performing critical functions like signal transduction and growth factor activation.
Unlike soluble proteases, they cleave peptide bonds within hydrophobic membrane domains, requiring unique structural adaptations.

Purpose of the Study:

To elucidate the structural features and mechanisms of intramembrane proteases.
To understand how these enzymes interact with membrane-embedded substrates and access their active sites.

Main Methods:

X-ray crystallography was used to determine the structure of intramembrane proteases, including Escherichia coli GlpG.
Electron microscopy and biochemical methods provided complementary data on structure and function.

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Related Experiment Videos

Last Updated: Jul 12, 2026

X-Ray Crystallography to Study the Oligomeric State Transition of the Thermotoga maritima M42 Aminopeptidase TmPep1050

X-Ray Crystallography to Study the Oligomeric State Transition of the Thermotoga maritima M42 Aminopeptidase TmPep1050

Published on: May 13, 2020

Unraveling Entropic Rate Acceleration Induced by Solvent Dynamics in Membrane Enzymes

Unraveling Entropic Rate Acceleration Induced by Solvent Dynamics in Membrane Enzymes

Published on: January 16, 2016

Exploring Caspase Mutations and Post-Translational Modification by Molecular Modeling Approaches

Exploring Caspase Mutations and Post-Translational Modification by Molecular Modeling Approaches

Published on: October 13, 2022

Main Results:

The first crystal structure of an intramembrane protease, E. coli GlpG, was reported.
Studies revealed insights into the construction of these membrane proteins, water access to active sites, and substrate interactions.

Conclusions:

Recent structural and biochemical studies are beginning to unveil the functional mechanisms of intramembrane proteases.
Understanding these enzymes is key to deciphering various cellular processes involving membrane protein regulation.