Structure and mechanism of the two-component α-helical pore-forming toxin YaxAB

• DOI: 10.1038/s41467-018-04139-2
• Publication Date: 2018-04-30T13:08:04Z
• Authors: Bastian Bräuning; Eva Bertosin; Florian Praetorius; Christian Ihling; Alexandra Schatt; Agnes Adler; Klaus Richter; Andrea Sinz; Hendrik Dietz; Michael Groll
• Keywords: Pore-forming toxin; Lytic cycle; Cryo-Electron Microscopy

Pore-forming toxins (PFT) are virulence factors that transform from soluble to membrane-bound states. The Yersinia YaxAB system represents a family of binary α-PFTs with orthologues in human, insect, and plant pathogens, unknown structures. was shown be cytotoxic likely involved pathogenesis, though the molecular basis for its two-component lytic mechanism remains elusive. Here, we present crystal structures YaxA YaxB, together cryo-electron microscopy map complex. Our reveal pore predominantly composed decamers YaxA-YaxB heterodimers. Both subunits bear membrane-active moieties, but only is capable binding membranes by itself. YaxB can subsequently recruited membrane-associated induced transmembrane helices. Pore formation progress further oligomerization dimers. results allow comparison between assemblies belonging wider ClyA-like α-PFTs, highlighting diverse architectures.