Fig. 5.

A superfamily (CATH 3.30.1130.10) containing enzymes with different EC numbers and gaining/losing a catalytic metal-binding site. The aligned protein structures (top), the aligned active sites with substrate-analogs bound (middle, the metal ion is depicted as a red sphere), and the structure-based alignment of the metal-binding ligands (bottom) are shown. The EC number of each enzyme is shown above the structure. (For interpretation of the references to color in this figure legend, the reader is referred to the web version of this article.)