Uncharacterized subfamily of ceruloplasmin homologous proteins. Ceruloplasmin (ferroxidase) is a multicopper oxidase essential for normal iron homeostasis. Ceruloplasmin also functions in copper transport, amine oxidase and as an antioxidant preventing free radicals in serum. The protein has 6 cupredoxin domains and exhibits internal sequence homology that appears to have evolved from the triplication of a sequence unit composed of two tandem cupredoxin domains. This model represents the first domain of the triplicated units.
Comment:Trinuclear copper site ligands are typically one or two HxH motifs that can be in the same domain/subunit or in different domains/subunits.
Comment:Human ceruloplasmin consists of six domains with one Type 1 (T1) copper each in domains 2, 4, and 6, as well as a catalytic trinuclear copper cluster at the interface between domains 6 and 1.
Jiyao W et al.(2023). "The conserved domain database in 2023.",