FIG. 3.

Robustness of the 3D reconstruction of the UL6 dodecamer with respect to the choice of starting model. (a) A resolution-limited, appropriately swollen, rendition of the bacteriophage φ29 portal led to (c), a model at 29-Å resolution, calculated from images of negatively stained molecules, which in turn led to (d) a model at 16-Å resolution calculated from cryoelectron micrographs. Starting the analysis with an entirely different, computer-generated, model (b) led to essentially the same result.