Figure 5 - full size

 

Figure 5.
Fig. 5. Environment of proposed catalytic water (shown with heavy black bonds). (a) Nuclear density (2F[o] – F[c]). (b) Atomic arrangement in the 1.8-Å-resolution neutron map. Both diagrams show the water molecule (with an elongated shape indicating two protons) and the two metal ion-carboxylate-water motifs. In the electron-density map (data not shown), two possible conformations exist for Asp-257, one of which agrees with the nuclear-density results shown here.