Figure 2.

Higher resolution AFM images of two-dimensional crystals of membrane-associated VacA oligomers. (a and b) Unprocessed AFM images show that the crystal consists of six-fold-symmetric VacA oligomers in a hexagonal array with lattice parameters a = b = 22 ± 1 nm, γ = 60° ± 5° (n = 31). The PDs from three nearest-neighbor oligomers are slightly higher than the centrally located hexameric ring. Notice that individual PDs can be detected at the edge of the crystal patch (arrow in a). (b) The arrow points to a region where one PD is missing, but the ring remains intact. (c) Processed AFM image after lattice unbending and six-fold symmetrization. The line diagram in the top right corner illustrates a single oligomer within the crystal with an overall diameter of ≈28 nm. Notice that the PD–connector orientation is similar to that observed at the edge of the crystal patch in a (arrow). (Bar = 15 nm.)