In molecular biology,multicopper oxidases areenzymes whichoxidise theirsubstrate by acceptingelectrons at a mononuclearcopper centre and transferring them to a trinuclear copper centre;dioxygenbinds to the trinuclear centre and, following the transfer of fourelectrons, isreduced to twomolecules ofwater.[1] There are threespectroscopically different copper centres found in multicopper oxidases: type 1 (or blue), type 2 (or normal) and type 3 (or coupled binuclear).[2][3] Multicopper oxidases consist of 2, 3 or 6 of thesehomologous domains, which also share homology with the cupredoxinsazurin andplastocyanin. Structurally, thesedomains consist of a cupredoxin-like fold, abeta-sandwich consisting of 7 strands in 2 beta-sheets, arranged in a Greek-keybeta-barrel.[4]
The family of multicopper oxidases can be divided into three groups based on the electron-donating substrate.[5] Laccases oxidize a variety of organic substrates, metalloxidases accept metal substrates and a third group contains multicopper oxidases that are specific towards one single substrate. Multicopper oxidases include:
^Ouzounis C, Sander C (February 1991). "A structure-derived sequence pattern for the detection of type I copper binding domains in distantly related proteins".FEBS Lett.279 (1):73–8.doi:10.1016/0014-5793(91)80254-Z.PMID1995346.S2CID10299194.
^Suzuki S, Kataoka K, Yamaguchi K (October 2000). "Metal coordination and mechanism of multicopper nitrite reductase".Acc. Chem. Res.33 (10):728–35.doi:10.1021/ar9900257.PMID11041837.
^Mann KG, Jenny RJ, Krishnaswamy S (1988). "Cofactor proteins in the assembly and expression of blood clotting enzyme complexes".Annu. Rev. Biochem.57:915–56.doi:10.1146/annurev.bi.57.070188.004411.PMID3052293.
^Askwith C, Eide D, Van Ho A, Bernard PS, Li L, Davis-Kaplan S, Sipe DM, Kaplan J (January 1994). "The FET3 gene of S. cerevisiae encodes a multicopper oxidase required for ferrous iron uptake".Cell.76 (2):403–10.doi:10.1016/0092-8674(94)90346-8.PMID8293473.S2CID27473253.
