XRD1 Highlights

Pore forming compounds are almost exclusively toxic peptides or proteins, which are expressed by the producing organism as water-soluble monomers, attracted by the membranes via specific receptors. The most studied pore-forming proteins are various families of bacterial toxins, termed pore-forming toxins (PFTs). Bacterial PFT serve as important virulence factors promoting bacterial spread through invading cells and tissues. However, PFTs are not limited to bacteria, and are found in many other organisms.
In this study we have determined the three dimensional atomic structure of the toxin from the earthworm Eisenia fetida, called lysenin. Lysenin is present in the coelomic fluid of earthworms and is produced to act defensively against parasitic microorganisms by forming pores.  The toxin is excreted by the defending cells, which are part of the immune system of the earthworm. It then

binds to cellular membranes and forms pores in them. Such damage usually leads to the death of the target cell
 

Crystal structure of an invertebrate cytolysin pore reveals unique properties and mechanism of assembly;
Podobnik M., Savory P., Rojko N., Kisovec M., Wood N., Hambley R., Pugh J., J. Wallace E., McNeill L., Bruce M., Liko I., Allison T. M., Mehmood S., Yilmaz N., Kobayashi T., Gilbert R. J. C., Robinson C. V., Jayasinghe L. and Anderluh G.
Nature Communications, 7:11598 (2016),
DOI: 10.1038/ncomms11598