Fig. 4. PRE-driven ensemble simulated annealing calculations characterizing the minor closed states of CaM with interdomain contacts.

(A,B) Dependence of the interdomain PRE Q-factor for S17C (blue) and A128C (green) as a function of (A) minor state population (using an 8-member ensemble) and (B) ensemble size (for a minor state population of 10%) for CaM-4Ca²⁺, apo CaM, and apo CaM + MLCK peptide. (C,D) The resulting fits to the PRE profiles for (C) S17C and (D) A128C for a minor state population of 10% represented by an 8-member ensemble (calculated, magenta lines; experimental, black circles; error bars, 1 s.d.).