Three-dimensional surface model of the p97 hexamer in the resting state (PDB 5FTK ). N domains are indicated in yellow, D1 domains in violet and D2/C terminal domains in red. The molecule is viewed from the front (left), back (middle) and side (right). Front and back views correspond well to the p97 structures observed by negative stain TEM ( n = 13,819 particles, 2.39 A per pixel, box size 120 pixels, particles were sorted and averaged in 100 classes). Side views were not found in class averages. When viewed from the side, the global shape of p97 can be inscribed into a truncated cone with the larger base corresponding to the D1 ring plus the peripheral N domains and the smaller base corresponding to the D2 ring.
