Figure 2  Molecular Dynamics Simulations of the GSK3/MAF Decapeptide Complexes
(A) Structural effects of the p.Pro59Leu and p.Pro59His changes. In both mutants, the conformation of the trimer comprised between the target and primed residues is considerably rearranged. Representative conformations are reported for wild-type MAF (left) and the p.Pro59Leu mutant (middle). In both mutants, larger and more variable distances are observed between the hydroxyl of Thr58, which is a GSK3 target residue, and the γ-phosphate of ATP (right, top plot) or the carboxyl group of the catalytic residue Asp181 (right, bottom plot). The distribution obtained in the simulations of the wild-type MAF sequence (black) and those referred to the peptides containing the p.Pro59His (red) and p.Pro59Leu (blue) substitutions are shown.
(B) Effect of the p.Pro69Arg change. In the simulations, a stable interaction between pSer70 of the wild-type peptide and the priming site was observed (left), while a displacement of that residue from the site was documented for the peptide carrying the p.Pro69Arg change (middle). Such structural rearrangements are quantified by the distance occurring between the P atom of pSer70 and the ω-carbon atom in the side chain of the GSK3 priming site residue, Arg180 (wild-type peptide, black; p.Pro69Arg peptide, green) (right). In the left and middle panels, the surface of GSK is colored in brown, except for the catalytic residue Asp181 (red), and the priming site residues, Arg96, Arg180, and Lys205 (blue). ATP is shown in pink and the MAF backbone in yellow. The side chains of priming, target, and mutated MAF residues are shown in sticks representation.