Toxin, which has some hemolytic activity towards mammalian cells. Acts by forming a pore-like structure upon contact with mammalian cells (By similarity). Monomer and oligomer. In periplasm, it is present as a monomer, while in outer membrane vesicles, it oligomerizes to form a pore structure that is active. The pore is formed by a dodecamer (By similarity). Exported from the cell by outer membrane vesicles. Also found in the periplasmic space (By similarity). In periplasm, it forms a disulfide bond, which prevents the oligomerization. In outer membrane vesicles, the redox status prevents formation of the disulfide bond, leading to oligomerization and pore formation (By similarity). Belongs to the hemolysin E family.