Pore-forming protein that causes membrane permeabilization and pyroptosis. Released upon cleavage by bacterial effector protein SpeB, and binds to membrane inner leaflet lipids. Homooligomerizes within the membrane and forms pores of 10-15 nanometers (nm) of inner diameter, triggering pyroptosis. Pyroptosis triggers the elimination of the infected skin cell, depriving the pathogen of its protective niche, while inducing an inflammatory response. This ultimately prevents bacterial penetration of the epithelial barrier and a subsequent systemic dissemination of the pathogen. Binds to cardiolipin and other acidic phospholipids, such as phosphatidylserine, which mediate its targeting to the inner leaflet membrane 