Formation of transmembrane pores is a very effective way of killing cells. It is thus not surprising that many bacterial and eukaryotic toxic agents are pore-forming proteins. Pore formation in a target membrane is a complex process composed of several steps; proteins need to attach to the lipid membrane, possibly aggregate in the plane of the membrane and finally form a pore by inserting part of the polypeptide chain across the lipid bilayer. Structural information about toxins at each stage is indispensible for the biochemical and molecular biological studies that aim to - derstand how...