... stuzeri C2,3O for 3,5-DMC and 3,6-DMC withrespect to unsubstituted catechol and to 3-DMC isfound (Table 1).The region facing positions 5 and 6 of the catecholring is mainly formed by a loop ... hin-drance between the substrate and the active site. Thisobservation and the reduced catalytic efficiency ofT249A C2,3O and T249G C2,3O with respect to thewild-type enzyme and to T249S C2,3O would ... 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...