Pathways & interactions
Short name: Cupredoxin
- Blue (type 1) copper domain (IPR000923)
- Blue (type 1) copper protein, plastocyanin-type (IPR001235)
- Rusticyanin (IPR001243)
- Copper centre Cu(A) (IPR001505)
- Ephrin receptor-binding domain (IPR001799)
- Amicyanin/Pseudoazurin (IPR002386)
- Plastocyanin (IPR002387)
- Cytochrome c oxidase subunit II-like C-terminal (IPR002429)
- Phytocyanin domain (IPR003245)
- Quinol oxidase subunit II (IPR006332)
- Cytochrome o ubiquinol oxidase subunit II (IPR006333)
- COX aromatic rich motif (IPR010514)
- Sulfocyanin (IPR010532)
- Multicopper oxidase, type 3 (IPR011707)
- Pseudoazurin (IPR012745)
- Amicyanin, Paracoccus/Methylobacterium (IPR013475)
- Protein-arginine deiminase (PAD) N-terminal (IPR013732)
- Azurin (IPR014068)
- Cytochrome c oxidase, subunit II (IPR014222)
- DP-EP family (IPR015078)
- Nitrosocyanin (IPR017527)
- Halocyanin, copper-binding domain (IPR017533)
- Ephrin, conserved site (IPR019765)
- Plastocyanin, cyanobacteria (IPR023511)
- PQQ system protein (IPR027590)
- EfeO-type cupredoxin-like domain (IPR028096)
- Blue (type 1) copper protein, binding site (IPR028871)
- Ephrin (IPR031328)
- Nitrous-oxide reductase, C-terminal (IPR034205)
- Cytochrome c oxidase subunit 2, C-terminal (IPR034210)
- Ba3-like heme-copper oxidase subunit II, C-terminal (IPR034214)
- Ubiquinol oxidase subunit 2, cupredoxin domain (IPR034227)
- Caa3-type Cytochrome c oxidase subunit II, cupredoxin domain (IPR034236)
- Methylamine utilization protein MauL (IPR034242)
- Sulfocyanin, C-terminal (IPR034246)
- Ephrin-A ectodomain (IPR034252)
- Ephrin-B ectodomain (IPR034255)
- Ascorbate oxidase, first cupredoxin domain (IPR034259)
- Ascorbate oxidase homologue, first cupredoxin domain (IPR034273)
- Copper resistance protein, first cupredoxin domain (IPR034284)
- Laccase, first cupredoxin domain (IPR034288)
- Amicyanin (IPR035668)
- PAD, N-terminal domain superfamily (IPR038685)
- Phytocyanin (IPR039391)
Copper is one of the most prevalent transition metals in living organisms and its biological function is intimately related to its redox properties. Since free copper is toxic, even at very low concentrations, its homeostasis in living organisms is tightly controlled by subtle molecular mechanisms. In eukaryotes, before being transported inside the cell via the high-affinity copper transporters of the CTR family, the copper (II) ion is reduced to copper (I). In blue copper proteins such as Cupredoxin, the copper (I) ion form is stabilised by a constrained His2Cys coordination environment.
This entry represents cupredoxin proteins, as well as structural homologues to cupredoxin. Structurally, the cupredoxin-like fold consists of a beta-sandwich with 7 strands in 2 beta-sheets, which is arranged in a Greek-key beta-barrel [PMID: 11867755]. Some of these proteins have lost the ability to bind copper. Proteins with a cupredoxin-type fold are found in the following family groups:
- Mono-domain cupredoxins, such as amicyanin, plastocyanin, pseudoazurin, plantacyanin, azurin, auracyanin, rusticyanin, stellacyanin, and mavicyanin.
- Multi-domain cupredoxins, such as nitrite reductase (2 domains of this fold), multicopper oxidase CueO, spore coat protein A, ascorbate oxidase (3 domains of this fold), laccase (3 domains of this fold), ceruloplamin (6 domains of this fold), and coagulation factor V.
- Red copper protein nitrocyanin and the C-terminal of nitrous oxide reductase.
- Quinol oxidase and the periplasmic domain of cytochrome c oxidase subunit II.
- Ephrin-a5 and ephrin-b2 ectodomain, which are related to cupredoxins but lack the metal-binding site.
- The N-terminal domain of protein arginine deiminase Pad4, which is related to cupredoxin but lacks the metal-biding site.