Pseudoazurin (IPR012745)

Short name: Pseudoazurin

Overlapping homologous superfamilies

Family relationships


Pseudoazurin, also called cupredoxin, is a small, blue periplasmic protein with a single bound copper atom. Pseudoazurin is related to plastocyanins [PMID: 8138527]. Several examples of pseudoazurin are encoded by a neighbouring gene for, or have been shown to transfer electrons to, copper-containing nitrite reductases (IPR001287) of the same species [PMID: 16138306].

Pseudoazurin has been identified as an electron donor to the denitrification pathway. For example, pseudoazurin acts as an electron donor to cytochrome c peroxidase and N2OR from Paracoccus pantotrophus [PMID: 22910335], and to the copper containing nitrite reductase that catalyzes the second step of denitrification [PMID: 15475344, PMID: 10364229]. It has been shown that pseudoazurin dramatically enhances the reaction profile of nitrite reduction by Paracoccus pantotrophus cytochrome cd1 and facilitates release of the product nitric oxide. The ability of this small redox protein to interact with a multitude of structurally different partners has been attributed to the hydrophobic character of the binding surface.

GO terms

Biological Process

No terms assigned in this category.

Molecular Function

GO:0005507 copper ion binding

Cellular Component

No terms assigned in this category.

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.