ジャーナル: Nat Commun / 年: 2018 タイトル: Structure and mechanism of the two-component α-helical pore-forming toxin YaxAB. 著者: Bastian Bräuning / Eva Bertosin / Florian Praetorius / Christian Ihling / Alexandra Schatt / Agnes Adler / Klaus Richter / Andrea Sinz / Hendrik Dietz / Michael Groll / 要旨: 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, ...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, with unknown structures. YaxAB was shown to be cytotoxic and likely involved in pathogenesis, though the molecular basis for its two-component lytic mechanism remains elusive. Here, we present crystal structures of YaxA and YaxB, together with a cryo-electron microscopy map of the YaxAB complex. Our structures reveal a pore predominantly composed of decamers of YaxA-YaxB heterodimers. Both subunits bear membrane-active moieties, but only YaxA is capable of binding to membranes by itself. YaxB can subsequently be recruited to membrane-associated YaxA and induced to present its lytic transmembrane helices. Pore formation can progress by further oligomerization of YaxA-YaxB dimers. Our results allow for a comparison between pore assemblies belonging to the wider ClyA-like family of α-PFTs, highlighting diverse pore architectures.
解像度: 4→48.82 Å / Cor.coef. Fo:Fc: 0.901 / Cor.coef. Fo:Fc free: 0.928 / SU B: 155.607 / SU ML: 0.904 / 交差検証法: THROUGHOUT / ESU R Free: 0.847 / 立体化学のターゲット値: MAXIMUM LIKELIHOOD / 詳細: HYDROGENS HAVE BEEN ADDED IN THE RIDING POSITIONS
Rfactor
反射数
%反射
Selection details
Rfree
0.33881
282
5 %
RANDOM
Rwork
0.32555
-
-
-
obs
0.32625
5351
98.65 %
-
溶媒の処理
イオンプローブ半径: 0.8 Å / 減衰半径: 0.8 Å / VDWプローブ半径: 1.2 Å / 溶媒モデル: MASK