The third cupredoxin domain of a multicopper oxidase McoC and similar proteins
This family includes bacteria multicopper oxidases (MCOs) represented by McoC from pathogenic bacterium Campylobacter jejuni. McoC is a periplasmic multicopper oxidase, which has been characterized to be associated with copper homeostasis. McoC may also function to protect against oxidative stress as it may convert metallic ions into their less toxic form. MCOs are multi-domain enzymes that are able to couple oxidation of substrates with reduction of dioxygen to water. They are capable of oxidizing a vast range of substrates, varying from aromatic compunds to inorganic compounds such as metals. Most MCOs 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 3 of 3-domain MCOs contains the Type 1 (T1) copper binding site and part the trinuclear copper binding site, which is located at the interface of domains 1 and 3.
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