Movie S3.

The structure of the CA-NTD determined by averaging of non-symmetry-related copies. The movie illustrates the averaging of non-symmetry-related CA-NTDs, and the resulting 5.5 Å resolution structure. The structure is also shown at a lower isosurface threshold to reveal density corresponding to the N-terminal part of the protein which is shown as a string of beads. See also Figure 4B and C.