The pore structure of Clostridium perfringens epsilon toxin

Christos G Savva,Richard W Titball,Ajit K Basak,David S Moss,Claire E Naylor,Alice R Clark,Monika Bokori-Brown,Michel R Popoff

doi:10.1038/s41467-019-10645-8

Abstract

Epsilon toxin (Etx), a potent pore forming toxin (PFT) produced by Clostridium perfringens, is responsible for the pathogenesis of enterotoxaemia of ruminants and has been suggested to play a role in multiple sclerosis in humans. Etx is a member of the aerolysin family of β-PFTs (aβ-PFTs). While the Etx soluble monomer structure was solved in 2004, Etx pore structure has remained elusive due to the difficulty of isolating the pore complex. Here we show the cryo-electron microscopy structure of Etx pore assembled on the membrane of susceptible cells. The pore structure explains important mutant phenotypes and suggests that the double β-barrel, a common feature of the aβ-PFTs, may be an important structural element in driving efficient pore formation. These insights provide the framework for the development of novel therapeutics to prevent human and animal infections, and are relevant for nano-biotechnology applications.

Highlights

Epsilon toxin (Etx), a potent pore forming toxin (PFT) produced by Clostridium perfringens, is responsible for the pathogenesis of enterotoxaemia of ruminants and has been suggested to play a role in multiple sclerosis in humans
Unlike aerolysin[37,38], Etx does not spontaneously oligomerize into sodium dodecyl sulfate (SDS)-resistant species when activated in aqueous buffer, and negatively stained EM samples do not reveal regular particles other than elongated monomers and small clumps (Supplementary Fig. 1a)
We assembled Etx oligomers that were biologically active towards Super Dome cells, a clone of Madin–Darby Canine Kidney (MDCK) cells that forms domes that are approximately five times the area of MDCK cells, exhibiting exceptional sensitivity to Etx[39]

Summary

Introduction

Epsilon toxin (Etx), a potent pore forming toxin (PFT) produced by Clostridium perfringens, is responsible for the pathogenesis of enterotoxaemia of ruminants and has been suggested to play a role in multiple sclerosis in humans. Etx monomers oligomerized and formed SDSresistant pores of an apparent molecular weight of ∼155 kDa on the membrane of Super Dome cells (Fig. 1b), consistent

Results

Conclusion