Laccase

Function

Laccase (Lac) is a multi-copper protein which uses molecular oxygen to oxidize various aromatic and non-aromatic compounds by a radical-catalyzed reaction mechanism</ref>^[1] CotA laccase belongs to the multi-copper oxidase family. The multi-copper oxidases constitute a family of enzymes whose principal members are laccase (benzenediol oxygen oxidoreductase, EC 1.10.3.2), ascorbate oxidase (L-ascorbate oxygen oxidoreductase, EC 1.10.3.3) and ceruloplasmin (Fe(II) oxygen oxidoreductase, EC 1.16.3.1). Similar to the other laccases the three dimensional structure of CotA 1w6l comprises three cupredoxin domains and four copper ions organised in : a and .^[2][3]

For laccase with nitrotyrosine modification see Nitrotyrosine.

Structural highlights

The trinuclear center of CotA laccase has two type 3 copper ions, that can be anti-ferromagnetically coupled through an hydroxyl moiety in between them, and one type 2 copper ion.‡ The mononuclear copper is able to accept an electron from a variety of phenolic substrates and then transmit it to the trinuclear centre.