Related Experiment Video
Updated: Aug 8, 2026

Sedimentation Equilibrium of a Small Oligomer-forming Membrane Protein: Effect of Histidine Protonation on Pentameric Stability
Published on: April 2, 2015
Structure of the hemolysin E (HlyE, ClyA, and SheA) channel in its membrane-bound form
Svetomir B Tzokov1, Neil R Wyborn, Timothy J Stillman
1Department of Molecular Biology and Biotechnology, Krebs Institute for Biomolecular Research, The University of Sheffield, Sheffield S10 2TN, United Kingdom.
Abstract:
Hemolysin E (HlyE, ClyA, SheA) is a pore-forming protein toxin isolated from Escherichia coli. The three-dimensional structure of its water-soluble form is known, but that of the membrane-bound HlyE complex is not. We have used electron microscopy and image processing to show that the pores are predominantly octameric. Three-dimensional reconstructions of HlyE pores assembled in lipid/detergent micelles suggest a degree of conformational variability in the octameric complexes. The reconstructed pores were significantly longer than the maximum dimension of the water-soluble molecule, indicating that conformational changes occur on pore formation.
Related Concept Videos
Lysosomal Hydrolases
Formation of Lipopolysaccharides
Asymmetric Lipid Bilayer
Viral Replication: Lytic Cycle
Protein Complex Assembly
Many viruses self-assemble into a fully functional unit using the infected host cell to...
Insertion of Single-pass Transmembrane Proteins in the RER
Integral transmembrane proteins possess transmembrane and extra membrane domains. The transmembrane domains are primarily made of 20-25 hydrophobic amino acids arranged in a helical secondary confirmation. These...
