Figure 4
Zn—Sγ distance (top) and Sγ—Zn—Sγ angle (bottom) distributions as a function of the number of cysteines and histidines in ZnCysxHisy complexes determined at 1.6 Å resolution or better. The contours of the violin plots are kernel density estimates and the box plots are shown as in Fig. 2 . The light grey background areas show one standard deviation around the refinement targets for the Zn—Sγ distance (2.340 ± 0.020 Å) and the Sγ—Zn—Sγ angle (109.5 ± 3.0°). The difference between the types of ZnCysxHisy complexes is significant (see Table 1 ). When Zn is coordinated by Nδ in ZnCys3His1 complexes, the Sγ—Zn—Sγ angle distribution is somewhat bimodal and partly depends on the rotameric state and backbone conformation of the cysteines. |