Alpha-toxin binds to the membrane of eukaryotic cells resulting in the release of low-molecular weight molecules and leading to an eventual osmotic lysis. Inhibits host neutrophil chemotaxis to the lesion region (Probable). Heptamer oligomerization and pore formation is required for lytic activity (By similarity). Self-assembles to form first a non-lytic oligomeric intermediate and then, a mushroom-shaped homoheptamer structure of 100 Angstroms in length and up to 100 Angstroms in diameter. Secreted as a monomer. After oligomerization and pore formation, the complex is translocated across the bilayer, probably via the Gly-rich domain of each strand. Less protein is secreted in a secG or double secG/secY2 mutant (at protein level). The mushroom-shaped heptamer is composed of a cap domain (comprising 7 beta sandwiches and the amino latches of each protomer), 7 rim regions whose protruding strands may interact with the membrane bilayer, and the stem domain (52 Angstroms in length, 26 Angstroms in diameter) which forms the transmembrane pore. About 10-fold decrease in virulence in mice, increased presence of neutrophils in the injection region. Belongs to the aerolysin family.