Figure 5: Proposed pore formation mechanism.
From: Molecular basis of transmembrane beta-barrel formation of staphylococcal pore-forming toxins
(Step 1): each PFT is secreted as soluble monomer. (Step 2): Hlg2 and LukF form a dimer on the cell surface. By releasing the amino latch located beside the cap domain, interprotomer interactions are formed adequately. (Step 3): the prestem extends due to attack by the released amino latch. On extension, the prestem is completely unfolded. (Step 4): dimers assemble to octameric prepore. In the prepore state, only the extramembrane half of the β-barrel is formed. (Step 5): the transmembrane half of the β-barrel is inserted into the membrane, and pore formation is completed.
