Crystal structure of listeriolysin O reveals molecular details of oligomerization and pore formation

The cytolysin, listeriolysin O (LLO), is expressed by Listeria and forms pores in the phagosomal membrane in response to decreased pH. Here, Yildiz et al. solve the crystal structure of LLO, identify residues that serve as the pH sensor, and determine the mechanism of pore formation in host membranes.