Figure 3 A = 180° section of the self-rotation function calculated from the squid calexcitin data set using a radius of integration of 20.0  Å and data to a resolution of 2.5  Å. The strongest peaks on the horizontal and vertical axes arise from space-group symmetry (P212121). The other peaks on the circumference are around 1/3 of the height of the crystallographic twofold peaks and suggest the presence of non-crystallographic twofold axes perpendicular to c and oriented at approximately 45° from the a and b axes.

© International Union of Crystallography 2005