Blue Copper protein family

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Last update: 2021-12-02 (Bruno Savelli)

Early nodulin, Plantacyanin, Plastocyanin, Stellacyanin, Uclacyanin, Other cupredoxin Protein


Plastocyanin-like domain :
This family is a plant-specific phytocyanins which constitute a distinct subfamily related to the copper binding protein plastocyanin. The family can be subdivided into the families of uclacyanins, stellacyanins, plantacyanins, and early nodulins. Stellacyanins have a blue copper coordinated by two His, one Cys and one Gln. In plantacyanins and uclacyanins, the ligands of the type-I Cu sites are two His, one Cys and one Met [PUBMED:9761472, PUBMED:11085657, PUBMED:15858169, PUBMED:15631465]. Early nodulins lack amino acid residues that coordinate Cu, so they are believed to be involved in unknown processes without binding Cu [PUBMED:19897921]. Phytocyanins are found in chloropasts of higher plants. The phytocyanin domain has a core of seven polypeptide strands arranged as a beta-sandwich comprising two beta-sheets, beta-sheet I and beta-sheet II. Beta-sheet I consists of three beta-strands and beta-sheet II consists of four beta-strands. A disulfide bridge close the metal centre is characteristic for phytocyanins, in contrast to azurins, pseudoazurins, and plastocyanins, where a disulfide bond is located on the distal side of the beta-barrel. This disuldide bridge may play a crucial role in maintaining the tertiary structure of the protein and/or the formation of the copper binding centre because one of the His ligands of copper is followed directly by a bridging Cys residue [PUBMED:9761472, PUBMED:11085657, PUBMED:15858169, PUBMED:15631465]
Copper binding proteins, plastocyanin/azurin family

Plastocyanin/azurin family of copper-binding proteins (or blue (type 1) copper domain) is a family of small proteins that bind a single copper atom. The most well-known members of this class of proteins are the plant chloroplastic plastocyanins, which exchange electrons with cytochrome c6, and the distantly related bacterial azurins, which exchange electrons with cytochrome c551.
Multicopper oxidase (Ascorbate oxidase and Laccase)

They oxidise their substrate by accepting electrons at a mononuclear copper centre and transferring them to a trinuclear copper centre; dioxygen binds to the trinuclear centre and, following the transfer of four electrons, is reduced to two molecules of water


Plastocyanin-like domain :
Pfam: PF02298
Plastocyanin-like domain
Interpro: IPR003245
Plastocyanin-like domain; IPR008972
Copper binding proteins
plastocyanin/azurin family
Pfam: PF00127
Copper binding proteins
plastocyanin/azurin family
Interpro: IPR008972
Cupredoxin; IPR000923
Blue (type 1) copper domain (BlueCu_1); IIPR028871
BlueCu_1_BS; IPR001235
Copper_blue_Plastocyanin.; IPR002387
Multicopper oxidase (Ascorbate oxidase and Laccase)
Pfam: PF00394
Cu-oxidase; PF07731
Cu-oxidase_2; PF07732
Interpro: IPR001117
Cu-oxidase.; IPR011706
Cu-oxidase_2; IPR011707
Cu-oxidase_3; IPR033138
Cu_oxidase_CS; IPR002355
Cu_oxidase_Cu_BS; IPR008972
Cupredoxin; IPR017760
L-ascorbate_oxidase_pln (specific Ascorbat Ox); IPR017761
Laccase (specific Laccases)


De Rienzo F, Gabdoulline RR, Menziani MC, Wade RC. Blue copper proteins: a comparative analysis of their molecular interaction properties.Protein Sci. 2000 Aug;9(8):1439-54.PMID:10975566.
Vasin A, Klotchenko S, Puchkova L. Phylogenetic analysis of six-domain multi-copper blue proteins. PLoS Curr. 2013 Mar 13;5.PMID:23516668