%0 Journal Article %A Hunt, Stuart %A Moir, Arthur J. G. %A Tzokov, Svetomir %A Bullough, Per A. %A Artymiuk, Peter J. %A Green, Jeffrey %T The formation and structure of Escherichia coli K-12 haemolysin E pores %D 2008 %J Microbiology, %V 154 %N 2 %P 633-642 %@ 1465-2080 %R https://doi.org/10.1099/mic.0.2007/011700-0 %K β-OG, n-octyl β-d-glucopyranoside %I Microbiology Society, %X Some enteric bacteria synthesize a pore-forming toxin, HlyE, which is cytolytic and cytotoxic to host cells. Measurement of HlyE binding to erythrocyte ghosts and the kinetics of HlyE-mediated erythrocyte lysis suggests that interaction with target membranes is not the rate-limiting step in the formation of HlyE pores, but that there is a temperature-dependent lag phase before a functional pore is formed. Circular dichroism and fluorescence energy transfer analyses show that HlyE protomers retain an α-helical structure when oligomerized to form a pore consisting of parallel HlyE protomers. Comparison of the proteolytic sensitivities of the water-soluble and oligomeric forms of HlyE identifies inner and outer surfaces of the pore. This new information has been used to constrain a model of the HlyE pore, which allows a more detailed interpretation of previous low-resolution 3D reconstructions and suggests a novel mechanism for insertion of HlyE into target membranes. %U https://www.microbiologyresearch.org/content/journal/micro/10.1099/mic.0.2007/011700-0