Crystal structures of copper-depleted and copper-bound fungal pro-tyrosinase: Insights into endogenous cysteine-dependent copper incorporation

Background: Fungal tyrosinase maturation involves multiple processes of the dinuclear copper assembly and proteolytic activation. Results: Structural examinations and mutational studies of the pro-tyrosinases revealed that three endogenous cysteines contribute to the copper incorporation. Conclusion: The three highly flexible cysteines are essential for assembly of the active site across the protein shell. Significance: Elucidation of such a copper incorporation process provides useful insights into metal homeostasis.