Laccases are multi-copper oxidoreductases able to oxidise a wide variety of phenolic and non-phenolic compounds and are widely distributed among both prokaryotes and eukaryotes. There are two main active catalytic sites with conserved histidines that are capable of binding four copper atoms [1].

1: Novel polyphenol oxidase mined from a metagenome expression library of bovine rumen: biochemical properties, structural analysis, and phylogenetic relationships. Beloqui A, Pita M, Polaina J, Martinez-Arias A, Golyshina OV, Zumarraga M, Yakimov MM, Garcia-Arellano H, Alcalde M, Fernandez VM, Elborough K, Andreu JM, Ballesteros A, Plou FJ, Timmis KN, Ferrer M, Golyshin PN; J Biol Chem. 2006;281:22933-22942. PMID:16740638