The second cupredoxin domain of CopA copper resistance protein like family
The members of this family are copper resistance protein (CopA) homologs. CopA is multicopper oxidase (MCO) related to laccase and L-ascorbate oxidase, both copper-containing enzymes. CopA is involved in copper resistance in bacteria. CopA mutant causes a loss of function, including copper tolerance and oxidase activity, and copA transcription is inducible in the presence of copper. Although MCOs have diverse functions, majority of them have three cupredoxin domain repeats that include one mononuclear and one trinuclear copper center. 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 center and transferring them to the active site trinuclear copper center. The cupredoxin domain 2 of 3-domain MCOs has lost the ability to bind copper.
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