Figure 3.

Height measurements of both the membrane-associated and water-soluble VacA oligomers. The cross-sectional profile along the line is shown at the bottom of each figure. (a) The height by which VacA complex protrudes from the bilayer is ≈3 nm, as determined from the edge of the crystal patch. Because the bilayer thickness is ≈5 nm (13), the maximal height of the membrane-associated oligomer is ≈8 nm. (b) Water-soluble VacA oligomers were directly adsorbed to mica, and a defect within the sample was created by the AFM tip with high force and high scan rate. The total height measured from the edge of this defect is ≈10 nm. These results were reproducible with or without chemical fixation. [Bar = 50 nm (a), 200 nm (b).]