Quercetin 2,3-dioxygenase
In enzymology, a quercetin 2,3-dioxygenase (EC 1.13.11.24) is an enzyme that catalyzes the chemical reaction
- quercetin + O2 2-(3,4-dihydroxybenzoyloxy)-4,6-dihydroxybenzoate + CO + H+
| quercetin 2,3-dioxygenase | |||||||||
|---|---|---|---|---|---|---|---|---|---|
 Crystal structure of quercetin 2,3-dioxygenase from pdb entry 1H1I with quercetin and copper. | |||||||||
| Identifiers | |||||||||
| EC number | 1.13.11.24 | ||||||||
| CAS number | 9075-67-6 | ||||||||
| Databases | |||||||||
| IntEnz | IntEnz view | ||||||||
| BRENDA | BRENDA entry | ||||||||
| ExPASy | NiceZyme view | ||||||||
| KEGG | KEGG entry | ||||||||
| MetaCyc | metabolic pathway | ||||||||
| PRIAM | profile | ||||||||
| PDB structures | RCSB PDB PDBe PDBsum | ||||||||
| Gene Ontology | AmiGO / QuickGO | ||||||||
| |||||||||
Thus, the two substrates of this enzyme are quercetin and O2, whereas its 3 products are 2-(3,4-dihydroxybenzoyloxy)-4,6-dihydroxybenzoate, CO, and H+.
This enzyme belongs to the family of oxidoreductases, specifically those acting on single donors with O2 as oxidant and incorporation of two atoms of oxygen into the substrate (oxygenases). The oxygen incorporated need not be derived from O2. The systematic name of this enzyme class is quercetin:oxygen 2,3-oxidoreductase (decyclizing). Other names in common use include quercetinase, and flavonol 2,4-oxygenase. It has 2 cofactors: iron, and Copper.
Structural studies
As of late 2007, 6 crystal structures have been solved for this class of enzymes, with PDB accession codes 1GQG, 1GQH, 1H1I, 1H1M, 1JUH, and 2H0V.
References
- Oka T, Simpson FJ (1971). "Quercetinase, a dioxygenase containing copper". Biochem. Biophys. Res. Commun. 43 (1): 1–5. doi:10.1016/S0006-291X(71)80076-1. PMID 5579942.
- Steiner RA, Kalk KH, Dijkstra BW (2002). "Anaerobic enzyme⋅substrate structures provide insight into the reaction mechanism of the copper-dependent quercetin 2,3-dioxygenase". Proc. Natl. Acad. Sci. U.S.A. 99 (26): 16625–30. Bibcode:2002PNAS...9916625S. doi:10.1073/pnas.262506299. PMC 139194. PMID 12486225.
- Bowater L, Fairhurst SA, Just VJ, Bornemann S (2004). "Bacillus subtilis YxaG is a novel Fe-containing quercetin 2,3-dioxygenase". FEBS Lett. 557 (1–3): 45–8. doi:10.1016/S0014-5793(03)01439-X. PMID 14741339. S2CID 45729959.