Figure 2.

Analysis of Asp23 distribution. Section plane affects the appearance of cellular structures in electron micrographs. (a) With an increasing section angle across the cell envelope the cell wall appears progressively blurred. Original images and schemes showing the degree of cell wall blur (b). The average position of the cell wall can be estimated using the extent of cell wall blurring and the distance of the section plane from middle of the cell (see Supplementary Information for details). (c) Original images and schemes showing that orientation of cell sections during immunodetection of antigen and (d) the linkage error affects the apparent localization of the antigen in electron micrographs. (e) 3D reconstruction of Asp23 distribution from immunofluorescence signals, (i and ii) amaP mutant and (iii) wild type. Volumes of Asp23 localization are shown with borders defined by the lateral fluorescence signal and the thickness of the section. For a better 3D visualization of Asp23 in the wild type, a blue sphere was drawn filling the cell lumen. (f) 3D reconstruction based on ssEM, orange and red spheres show the distribution of immunogold labeled Asp23 molecules, taking into account a linkage error of 40 nm, (i) amaP mutant and (ii) wild type. Blue elements mark the position of nucleoids. Lines indicate the position of the cell wall/cell membrane interface as deduced from the electron micrographs.