Figure 3.

Cross correlation and mean square fluctuations. Plots of (a) the cross correlation of the residue motions and the distance between the C_α atoms, and (b) the mean square fluctuations of each residue for LAC (pdb: 1EFA). The cross correlation of the C_α atom motion is calculated from Equation 11 which defines how similar the motion direction is, 1 is identical motion, 0 is completely different motion, while -1 is exactly inverse motion. The mean square fluctuations of each residue is calculated from Equation 12 and represents how much the distance between each residue varies during the natural protein motion.