FIGURE 1.

PilJ expression and localization. A, electron micrographs stained with anti-PilA1 and anti-PilJ antibodies and immunogold-labeled secondary antibodies with particle sizes 10 nm (PilA1) and 15 nm (PilJ). Nanoparticles associated with pili are labeled with either gray triangles (10 nm, PilA1) or black triangles (15 nm, PilJ). B, quantification of immunogold labeling. The average number of particles per field is shown as a horizontal line. The error bars show one standard deviation.