Figure 8.

(A) PC1 (left) and PC2 (right) compared against the NMR structures of the human apo protein (blue; PDB: 2L0P) (26) and the human holo protein (red; PDB: 2LP3) (29). Movement of the respective PCs is in the direction from apo, indicated by (−), to holo, indicated by (+), as shown by the black arrows. PC1 is characterized by the swinging of the third helix away from the helical bundle. PC2 is characterized by the rotation of the third helix and the tilting of the fourth helix, both away from the helical bundle. (B) PCA for the four MD trajectories of the apo (blue), holo (red), and half-saturated (green) proteins, with NMR structures indicated as black dots. The half-saturated system samples intermediate regions along PC1 between the apo and holo states. To see this figure in color, go online.