Figure 5. Alteration in local dynamics in phenylalanine hydroxylase upon side chain oxidation.

Residue-wise B-factors for the 2*16 REMD trajectories were calculated for Cα-atoms and compared between simulations of equal temperatures. Rank-based differences were mapped on the protein structure, where blue regions indicate regions more flexible in more of the 16 simulations of PAH_nat. Unaffected regions are shown in white, whereas red regions indicate regions showing elevated backbone dynamics in more of the 16 simulations of PAH_ox. Elevated B-factors in the central helices suggest an allosteric signal transduction over this path from the introduced oxidation site (Cys203, Cys334) to the Tyr138-loop near the catalytic center. The bottom picture shows the same structure rotated by 220° to highlight local effects on the oxidation site in the back of the top picture.