Azurin is a blue copper-binding protein in the plastocyanin/azurin family (see pfam00127). It serves as a redox partner to enzymes such as nitrite reductase or arsenite oxidase. The most closely related copper-binding proteins to this family are auracyanins, as in Chloroflexus aurantiacus, which have similar redox activities. [Energy metabolism, Electron transport]
Jiyao W et al.(2023). "The conserved domain database in 2023.",