Figure 3. Molecular Replacement Solution of Factor D.

a) Self Rotation Function. The unit cell axis vectors (a,b,c) are superimposed on the unit sphere. The polar angles values phi (longitudes) and psi (latitudes) are shown in 15 degree increments. All peaks in the rotation function of at least 2 standard deviations (sigma) above background are shown as cones. The size and shading of the cones reflect the value of the function. A vector from the origin to the largest peak marks the direction of the observed pseudo-two fold.
b) Cross Rotation Function. The unique Eulerian angle space is represented as a 3D grid. All peaks of at least 4 sigma are shown as semi-transparent cubes. Axes labeled X,Y,Z are centered at the two observed peaks. The axes have been rotated by the eulerian angles of the peak. It may be seen that these peaks are related by a two-fold.
c) Translation Function. The unit cell box is shown with the origin and axes labelled. All peaks in the R-factor search translation function of at least 3 sigma are shown as semi-transparent cubes. The size and shading of the cubes reflect the value of the function. Each monomer is represented as an ellipsoid fit to the model structure. A vector from the largest peak to the closest origin (+X,+Z) marks the solution. The 2-fold axis determined from the self rotation function is also displayed at the midpoint of the translation vector. This point was chosen as the origin of the cell (arbitrary in P1) to simplify the non-crystallographic symmetry analysis.