Mugineic-acid 3-dioxygenase
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Mugineic-acid 3-dioxygenase (EC 1.14.11.25, IDS2) is an enzyme with systematic name mugineic acid,2-oxoglutarate:oxygen oxidoreductase (3-hydroxylating).[1][2] This enzyme catalyses the following chemical reaction
| Mugineic-acid 3-dioxygenase | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| Identifiers | |||||||||
| EC no. | 1.14.11.25 | ||||||||
| Databases | |||||||||
| BRENDA | enzyme data | ||||||||
| ExPASy | NiceZyme view | ||||||||
| KEGG | enzyme entry | ||||||||
| MetaCyc | metabolic pathway | ||||||||
| Rhea | reactions | ||||||||
| PDB structures | RCSB PDB PDBe PDBsum | ||||||||
| |||||||||
It can also catalyse the related reaction:[3]
Mugineic acid is an amino acid excreted by some graminaceous (grassy) plants under conditions of iron deficiency as part of a strategy of solubilizing Fe(III) from the root environment for uptake by the plant. Mugineic acid is closely related to its biochemical precursor, nicotianamine, and to a number of other compounds that also have been identified as phytosiderophores in graminaceous plants: 3-hydroxymugineic acid, 2'-deoxymugineic acid, avenic acid, and distichonic acid.
The effectiveness of mugineic acid under iron-deficient conditions is dependent not only upon the iron chelating properties of the Fe-mugineic acid complex itself but also upon the presence of a plant membrane carrier that recognizes and absorbs the Fe-mugineic acid complex almost exclusively.[4]
Mechanism
The enzyme is a 2-oxoglutarate-dependent oxygenase, which are non-heme iron proteins with ferryl active site where Fe(IV)=O is the species that transfers its oxygen to the substrate.[5]
The mechanism requires 2-oxoglutaric acid to activate the iron oxygen complex, and this gives succinic acid and carbon dioxide when the second atom of the molecular oxygen is removed.[6][7]
