... ECDs belongingto subfamilies 5 and 6, such as DHpCD and THTD,catalyze the transformation of 3,6-disubstituted and 4,5-disubstituted catechols, respectively [24–26], and exhibit high regioselectivity ... Michaelis–Menten relationship, theseresults indicate that a reduction of the volume of resi-due 249 increases the affinity of the enzyme for 3,5-DMC and 3,6-DMC and decreases the affinity for smaller substrates.Mutations ... kcatvalues with respect to those meas-ured for the wild-type enzyme; approximately four-fold and 20-fold for catechol and 3-MC, respectively. Onthe other hand, the behavior of the mutants is verydifferent...