Plastocyanin family of copper binding proteins
Encyclopedia
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 and that are characterised by an intense electronic absorption band near 600 nm (see copper proteins
). The most well-known members of this class of proteins are the plant chloroplastic plastocyanin
s, which exchange electrons with cytochrome
c6, and the distantly related bacterial azurins, which exchange electrons with cytochrome c551. This family of proteins also includes amicyanin
from bacteria such as Methylobacterium extorquens
or Paracoccus versutus (Thiobacillus versutus) that can grow on methylamine; auracyanins A and B from Chloroflexus aurantiacus
; blue copper protein from Alcaligenes faecalis
; cupredoxin (CPC) from Cucumis sativus (Cucumber) peelings; cusacyanin (basic blue protein; plantacyanin, CBP) from cucumber; halocyanin from Natronomonas pharaonis (Natronobacterium pharaonis), a membrane-associated copper-binding protein; pseudoazurin from Pseudomonas; rusticyanin from Thiobacillus ferrooxidans; stellacyanin from Rhus vernicifera (Japanese lacquer tree); umecyanin from the roots of Armoracia rusticana (Horseradish); and allergen Ra3 from ragweed. This pollen protein has evolutary relation to the above proteins, but seems to have lost the ability to bind copper. Although there is an appreciable amount of divergence in the sequences of all these proteins, the copper ligand sites are conserved.
Protein family
A protein family is a group of evolutionarily-related proteins, and is often nearly synonymous with gene family. The term protein family should not be confused with family as it is used in taxonomy....
of small proteins that bind a single copper atom and that are characterised by an intense electronic absorption band near 600 nm (see copper proteins
Copper proteins
Copper proteins are proteins that contain one or more copper ions as prosthetic groups. The metal centres in the copper proteins can be classified into several types:...
). The most well-known members of this class of proteins are the plant chloroplastic plastocyanin
Plastocyanin
Plastocyanin is an important copper-containing protein involved in electron-transfer. The protein is monomeric, with a molecular weight around 10,500 Daltons, and 99 amino acids in most vascular plants...
s, which exchange electrons with cytochrome
Cytochrome
Cytochromes are, in general, membrane-bound hemoproteins that contain heme groups and carry out electron transport.They are found either as monomeric proteins or as subunits of bigger enzymatic complexes that catalyze redox reactions....
c6, and the distantly related bacterial azurins, which exchange electrons with cytochrome c551. This family of proteins also includes amicyanin
Amicyanin
Amicyanin is a type I copper protein that plays an integral role in electron transfer. In bacteria such as Paracoccus denitrificans, amicyanin is part of a three-member redox complex, along with methylamine dehydrogenase and cytochrome c-551i....
from bacteria such as Methylobacterium extorquens
Methylobacterium extorquens
Methylobacterium extorquens is a Gram-negative bacterium....
or Paracoccus versutus (Thiobacillus versutus) that can grow on methylamine; auracyanins A and B from Chloroflexus aurantiacus
Chloroflexus aurantiacus
Chloroflexus aurantiacus is a photosynthetic bacterium isolated from hot springs, belonging to the green non-sulfur bacteria. This organism is thermophilic and can grow at temperatures from 35 °C to 70 °C. Chloroflexus aurantiacus can survive in the dark if oxygen is available. When grown in the...
; blue copper protein from Alcaligenes faecalis
Alcaligenes faecalis
Alcaligenes faecalis is a Gram-negative, rod-shaped, motile, non-nitrate reducing, oxidase positive, catalase positive, beta hemolytic, and citrate positive obligate aerobe that is commonly found in the environment. It was originally named for its first discovery in feces, but was later found to be...
; cupredoxin (CPC) from Cucumis sativus (Cucumber) peelings; cusacyanin (basic blue protein; plantacyanin, CBP) from cucumber; halocyanin from Natronomonas pharaonis (Natronobacterium pharaonis), a membrane-associated copper-binding protein; pseudoazurin from Pseudomonas; rusticyanin from Thiobacillus ferrooxidans; stellacyanin from Rhus vernicifera (Japanese lacquer tree); umecyanin from the roots of Armoracia rusticana (Horseradish); and allergen Ra3 from ragweed. This pollen protein has evolutary relation to the above proteins, but seems to have lost the ability to bind copper. Although there is an appreciable amount of divergence in the sequences of all these proteins, the copper ligand sites are conserved.