RT Journal Article
SR Electronic
T1 Structural basis for tuning activity and membrane specificity of bacterial cytolysins
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 2020.06.16.154724
DO 10.1101/2020.06.16.154724
A1 Shah, Nita R.
A1 Voisin, Tomas B.
A1 Parsons, Edward S.
A1 Boyd, Courtney M.
A1 Hoogenboom, Bart W.
A1 Bubeck, Doryen
YR 2020
UL http://biorxiv.org/content/early/2020/06/17/2020.06.16.154724.abstract
AB Cholesterol-dependent cytolysins (CDCs) form protein nanopores to lyse cells. They target eukaryotic cells using different mechanisms, but all require the presence of cholesterol to pierce lipid bilayers. How CDCs use cholesterol to selectively lyse cells is essential for understanding virulence strategies of several pathogenic bacteria, and for repurposing CDCs to kill new cellular targets. Here we address that question by trapping an early state of pore formation for the CDC intermedilysin, bound to the human immune receptor CD59 in a nanodisc model membrane. Our cryo-electron microscopy map reveals structural transitions required for oligomerization, which include the lateral movement of a key amphipathic helix. We demonstrate that the charge of this helix is crucial for tuning lytic activity of CDCs. Furthermore, we discover modifications that overcome the requirement of cholesterol for membrane rupture, which will facilitate engineering the target-cell specificity of pore-forming proteins.Competing Interest StatementThe authors have declared no competing interest.