Figure 2.

In situ localization of the SOD trimer. Projection maps of the cell envelope with imposed p6 symmetry at 4.5 Å resolution were obtained from (A) six averaged images with dominant top views (extracellular face, as shown in the schematic representation of the cell envelope on the bottom left) and (B) six averaged images with dominant bottom views (cytosolic face, as shown in the schematic representation of the cell envelope on the top right). In the round insets below the maps, it is shown the DR_2577 top view (center left) and the DR_0644 bottom view (center right), respectively, fitted in the map. The remaining insets show a detail of the two maps and of the convoluted particles. From the fitting of the bottom view, it is evident that the collar region can be only partially explained by the contribution of the DR_0644 trimer. For both insets, the atomic models where convoluted into a 4.5 Å particle. The scale indicates 50 Å.