Figure 5.

Potential coupling between exposure and phosphorylation of Y88 and Y74. Shown are selected free-energy profiles showing (A) the equilibrium between buried and solvent-exposed Y74 states when Y88 is either phosphorylated or not; the relationship between the degree of exposure of Y74 and either (B) Y88 or (C) pY88; the relationship between the number of contacts in the β-sheet formed between p27 and Cdk2; and the degree of exposure of Y74 either with (E) Y88 or (F) pY88. The free-energy profiles are based on the parallel-bias metadynamics simulations (Table S1, Refs. G (Y88) and H (pY88)). (D) Illustrated is the location of the β-sheet formed between p27 and Cdk2 whose number of contacts are used (E and F). To see this figure in color, go online.