Modifications of laccase activities of copper efflux oxidase, CueO by synergistic mutations in the first and second coordination spheres of the type I copper center

► The redox potential of type I copper in a multicopper oxidase CueO was shifted to positive or negative direction. ► Enzymatic activities of CueO was tuned by modifications in the first and second coordination spheres of type I copper. ► Synergistic effect of mutations was attained maximally 140-fold compared to the wild type enzyme.