Figure 4.

The zinc-coordinating His residue populates many rotameric states in ZF1 but only one state in ZF2. Top: probability density distributions of the stacking angle and distance between the stacked aromatic rings are shown for His279 and His296 in MEX-5 ZF1 (left) and for Phe323 and His341 in MEX-5 ZF2 (right). The color bars show the values of the probability density calculated for the stacking angle and distance as the number of counts normalized by the total number of observations and by the area of each bin. Configurations and distributions were extracted from three 50-ns MD trajectories. Bottom: probability distributions of the dihedral angle χ₂ are shown for the zinc-coordinating histidines H296 (left) and H341 (right). To see this figure in color, go online.