Related Experiment Video
Updated: Aug 1, 2026

Monitoring the Assembly of a Secreted Bacterial Virulence Factor Using Site-specific Crosslinking
Published on: December 17, 2013
Structural and biochemical characterization of the type III secretion chaperones CesT and SigE
1Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver V6T 1Z3, Canada.
Abstract:
Several Gram-negative bacterial pathogens have evolved a type III secretion system to deliver virulence effector proteins directly into eukaryotic cells, a process essential for disease. This specialized secretion process requires customized chaperones specific for particular effector proteins. The crystal structures of the enterohemorrhagic Escherichia coli O157:H7 Tir-specific chaperone CesT and the Salmonella enterica SigD-specific chaperone SigE reveal a common overall fold and formation of homodimers. Site-directed mutagenesis suggests that variable, delocalized hydrophobic surfaces observed on the chaperone homodimers are responsible for specific binding to a particular effector protein. Isothermal titration calorimetry studies of Tir-CesT and enzymatic activity profiles of SigD-SigE indicate that the effector proteins are not globally unfolded in the presence of their cognate chaperones.
More Related Videos
09:05High Resolution Electron Microscopy of the Helicobacter pylori Cag Type IV Secretion System Pili Produced in Varying Conditions of Iron Availability
Published on: November 21, 2014
13:11Super-Resolution Imaging of Bacterial Secreted Proteins Using Genetic Code Expansion
Published on: February 10, 2023
Related Concept Videos
Molecular Chaperones and Protein Folding
The...
Overview of Secretory Vesicles
Various proteins regulate the aggregation of molecules inside the secretory vesicles. Chromogranins...
Tail-anchoring of Proteins in the ER Membrane
Chemotaxis in E. coli