Crosstalk between plasma membrane andStaphylococcusα-hemolysin during oligomerization

Summary The infectious microbe Staphylococcus aureus releases an array of cytotoxic pore-forming toxins (PFTs) that severely damage the cell membrane during bacterial infection. However, the interaction interfaces between the host cell and toxin were merely explored. Herein, we monitored the active oligomeric states facilitated membrane disruption processes such as lysis, and protrusion in the plasma membrane and lipid membrane. Furthermore, necrosis was triggered in the neutrophil-like cells upon synergistic binding and oligomerization of the monomeric α-HL. Additionally, we solved RBC membrane stabilized structure of different conformational states of this β-PFT using a single-particle cryo-EM. We further confirmed that internal membrane fluidity was the deterministic factor associated with the formation of intermediate pre-pores, heptameric pore-like, and complete pore species. Together, this is the first study to unveil the structure-function analysis of pre-pore to pore transition of any small β-PFT during its crosstalk with the cell. Highlights α-HL promotes necrosis in HL60 cells and lysis of shorter lipid bilayer region. Cryo-EM of small PFT in the cellular environment. Structural characterization of heptameric pore, pore-like, and pre-pore complex in the presence of RBCs. Bilayer phase behavior (Ld/Lo) governs different conformational and geometrical variants of α-HL. Competing Interest Statement The authors have declared no competing interest.