Conformational Changes during Pore Formation by the Perforin-Related Protein Pleurotolysin
Figure 3
Structure of the pleurotolysin pore.
(A) Cut away side and (B) tilted surface views of the cryo-EM reconstruction of a pleurotolysin pore with the fitted atomic structures. (C) Segment of the pore map corresponding to a single subunit with pore model fitted into the density. The PlyB crystal structure is superposed to show a 70° opening of the MACPF β-sheet (red) and movement of the HTH motif (cyan). TMH regions (yellow) are refolded into transmembrane β-hairpins. The PlyB C-terminal trefoil (green) sits on top of the PlyA dimer (pink). (D) Interface between TMH2, the HTH region, and the underlying sheet in the PlyB crystal structure. The position of the TMH2 helix lock (pink spheres) and TMH2 strand lock (grey spheres) are shown. The highly conserved “GG” motif (296–297) in the HTH region is represented as yellow spheres.