FIGURE 10.

Porcupine plots of (a) first and (c) second eigenvectors for simulation of model 3. (b) Top view of the motion described by the first eigenvector. The models are shown as a backbone trace. The arrows attached to each backbone atom indicate the direction of the eigenvector and the magnitude of the corresponding eigenvalue. Each 21-mer unit is colored in an alternating fashion of red and blue. The TTA linker loop is colored as yellow arrows. The arrows summarize the direction of motion. The motion in the first eigenvector correspond to rotary motion of the top tetrad unit (blue) in clockwise direction relative to the bottom tetrad (red) in an anticlockwise direction. The motion exhibited by the second eigenvector in (c) is identical to that observed for the first eigenvector in models 1 and 4.