Binding Site

Multicopper oxidase, copper-binding site (IPR002355)

Short name: Cu_oxidase_Cu_BS


The entry represents a conserved region containing the Cu-binding site found in multicopper oxidases.

Multicopper oxidases oxidise their substrate by accepting electrons at a mononuclear copper centre and transferring them to a trinuclear copper centre; dioxygen binds to the trinuclear centre and, following the transfer of four electrons, is reduced to two molecules of water [PMID: 16234932]. There are three spectroscopically different copper centres found in multicopper oxidases: type 1 (or blue), type 2 (or normal) and type 3 (or coupled binuclear) [PMID: 2404764, PMID: 1995346]. Multicopper oxidases consist of 2, 3 or 6 of these homologous domains, which also share homology to the cupredoxins azurin and plastocyanin. Structurally, these domains consist of a cupredoxin-like fold, a beta-sandwich consisting of 7 strands in 2 beta-sheets, arranged in a Greek-key beta-barrel [PMID: 11867755]. Multicopper oxidases include:

  • Ceruloplasmin (EC: (ferroxidase), a 6-domain enzyme found in the serum of mammals and birds that oxidizes different inorganic and organic substances; exhibits internal sequence homology that appears to have evolved from the triplication of a Cu-binding domain similar to that of laccase and ascorbate oxidase.
  • Laccase (EC: (urishiol oxidase), a 3-domain enzyme found in fungi and plants, which oxidizes different phenols and diamines. CueO is a laccase found in Escherichia coli that is involved in copper-resistance [PMID: 11867755].
  • Ascorbate oxidase (EC:, a 3-domain enzyme found in higher plants.
  • Nitrite reductase (EC:, a 2-domain enzyme containing type-1 and type-2 copper centres [PMID: 14572631, PMID: 11041837].

GO terms

Biological Process

No terms assigned in this category.

Molecular Function

GO:0005507 copper ion binding

Cellular Component

No terms assigned in this category.

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.
PROSITE patterns