STAPHYLOCOCCAL ALPHA-TOXIN, STREPTOLYSIN-O, AND ESCHERICHIA-COLI HEMOLYSIN - PROTOTYPES OF PORE-FORMING BACTERIAL CYTOLYSINS

Staphylococcal alpha-toxin, streptolysin-O, and Escherichia coli hemol ysin are well-studied prototypes of pore-forming bacterial cytotoxins. Each is produced as a water-soluble single-chain polypeptide that ins ets into target membranes to form aqueous transmembrane pores. This re view will compare properties of the three toxin prototypes, highlighti ng the similarities and also the differences in their structure, mode of binding, mechanism of pore formation, and the responses they elicit in target cells. Pore-forming toxins represent the most potent and ve rsatile weapons with which invading microbes damage the host macroorga nism.