InterPro domain: IPR034288

Laccase is a blue multicopper oxidase (MCO) which catalyzes the oxidation of a variety aromatic - notably phenolic and inorganic substances coupled to the reduction of molecular oxygen to water. Laccase has been implicated in a wide spectrum of biological activities and, in particular, plays a key role in morphogenesis, development and lignin metabolism. Plants usually express multiple laccase genes, but their precise physiological/biochemical roles remain largely unclear [ 1 ]. In cotton (Gossypium spp.), laccases may be involved in fibre development [ 2 ].

MCOs are capable of oxidizing a vast range of substrates, varying from aromatic compounds to inorganic compounds such as metals. Although the members of this family have diverse functions, majority of them have three cupredoxin domain repeats. The copper ions are bound in several sites: Type 1, Type 2, and/or Type 3. The ensemble of types 2 and 3 copper is called a trinuclear cluster. MCOs oxidize their substrate by accepting electrons at a mononuclear copper centre and transferring them to the active site trinuclear copper centre. The cupredoxin domain 1 of 3-domain MCOs contains part the trinuclear copper binding site, which is located at the interface of domains 1 and 3 [ 3 , 4 ].

1. The laccase multigene family in Arabidopsis thaliana: towards addressing the mystery of their gene function(s). Planta 233, 439-70
2. Genome-wide identification of multifunctional laccase gene family in cotton (Gossypium spp.); expression and biochemical analysis during fiber development. Sci Rep 6, 34309
3. Crystal structure of the type-2 Cu depleted laccase from Coprinus cinereus at 2.2 A resolution. Nat. Struct. Biol. 5, 310-6
4. Laccases: a never-ending story. Cell. Mol. Life Sci. 67, 369-85