Comparison of GNM and B Factor Profiles for CDK2. (A) Structural mapping of GNM dynamic modeling results for the apo form of CDK2 (PDB ID: 1 HCL; see Materials and Methods). The N-terminal lobe (top) is more flexible (red) when compared to the C-terminal lobe (blue). (B) Comparison of modal plots for the two largest amplitude fluctuations are shown for the apo (red) and ATP bound (blue) conformers of ATP. Flexible regions defined by the GNM differs from those defined by experimental temperature factors (dashed line). Locating bars at top represent (a) N-terminal lobe, (b) PSTAIRE helix, (c) T-Loop, and (d) G-loop.