Figure 3.

Different catalytic machinery performing same enzymatic chemistry. The three domains shown in this figure use different catalytic machineries to perform the same enzymatic reaction (EC 4.1.2.13). Each domain belongs to a different functional family in the Aldolase Class I superfamily (CATH 3.20.20.70). On the figure different regions in the active site are assigned to clusters 1–8. The catalytic residues in each cluster are reported to have the same functional properties, summarised on the figure. Each colour represents the catalytic residues of a different domain: red is 1aldA00, blue is 1b57A00, and green is 1ok4A00. The remaining portions of the three domains are coloured grey. The same catalytic residue is used by two or more domains in clusters 1, 6, and 7. Different catalytic residues are used in clusters 3 and 5 but still show enough physicochemical similarity to provide the same functionality. The proteins have different catalytic rates which may reflect their different catalytic machineries [51].