Fig 2.

Protein structures of various PFT classes. (A and B) Structures of a single molecule (A) and an assembled pore (B) of the E. coli α-PFT HlyE (295, 296) (Protein Data Bank [PDB] accession number 1QOY). (C) Structure of aerolysin, a β-PFT produced by A. hydrophila (485) (PDB accession number 1PRE). (D) PFO monomer (83) (PDB accession number 1PFO). (E) Hypothetical arrangement of CDC monomers into an assembled pore. This image was created by mapping PFO monomers onto a PLY cryo-electron microscopy (cryo-EM) image (180) (PDB accession number 2BK1). Structures were visualized using PyMOL (D) or MMDB (486) (A to C and E).