Galactose oxidase.

@article{Whittaker2002GalactoseO,
  title={Galactose oxidase.},
  author={James W. Whittaker},
  journal={Advances in protein chemistry},
  year={2002},
  volume={60},
  pages={1-49}
}
The free radical-coupled copper catalytic motif has emerged as the unifying feature of a new family of enzymes, the radical copper oxidases. Their highly evolved active sites include a novel amino acid modification, the Tyr-Cys dimer, that forms spontaneously through self-processing of the protein during its maturation. The active site is remarkable in the extent to which metal ligands participate in the catalytic process. Rather than simply coordinating the metal ion, the ligands perform… CONTINUE READING