Structural Basis for Highly Efficient Production of Catechol Derivatives at Acidic pH by Tyrosinase from Burkholderia thailandensis

Tyrosinases (TYRs) catalyze two-step consecutive oxidation reactions of monophenolic compounds. Since known TYRs have optimal pH at neutral to somewhat basic pH, they have limitations to be used for production of catechol derivatives. In this study, we identified TYR from Burkholderia thailandensis (BtTYR), which exhibited high tyrosinase activity at low pH. We determined the crystal structure of BtTYR and provided the structural basis for the regulation of its activity in response to pH change. At high pH, BtTYR is inactivated due to the tight binding of its TYR and CAP domains, although it is stable in monomer form; at low pH, however, the protein is activated by the typical opening of the CAP domain, and the formation of tetramers maintains the stability of the protein. Such unique tyrosinase activity of BtTYR at acidic pH was successfully applied to highly efficient production of catechol derivatives and fabrication of an adhesive hydrogel.