Thymine dioxygenase

In enzymology, a thymine dioxygenase (EC 1.14.11.6) is an enzyme that catalyzes the chemical reaction

thymine + 2-oxoglutarate + O₂ ${\displaystyle \rightleftharpoons }$ 5-hydroxymethyluracil + succinate + CO₂

The 3 substrates of this enzyme are thymine, 2-oxoglutarate, and O₂, whereas its 3 products are 5-hydroxymethyluracil, succinate, and CO₂.

This enzyme belongs to the family of oxidoreductases, specifically those acting on paired donors, with O2 as oxidant and incorporation or reduction of oxygen. The oxygen incorporated need not be derived from O2 with 2-oxoglutarate as one donor, and incorporation of one atom o oxygen into each donor. The systematic name of this enzyme class is thymine,2-oxoglutarate:oxygen oxidoreductase (7-hydroxylating). Other names in common use include thymine 7-hydroxylase, 5-hydroxy-methyluracil dioxygenase, and 5-hydroxymethyluracil oxygenase. It has 2 cofactors: iron, and Ascorbate.

References

• Bankel L, Holme E, Lindstedt G, Lindstedt S (1972). "Oxygenases involved in thymine and thymidine metabolism in Neurospora crassa". FEBS Lett. 21 (2): 135–138. doi:10.1016/0014-5793(72)80121-2. PMID 11946494.
• Liu CK, Hsu CA, Abbott MT (1973). "Catalysis of three sequential dioxygenase reactions by thymine 7-hydroxylase". Arch. Biochem. Biophys. 159 (1): 180–7. doi:10.1016/0003-9861(73)90443-8. PMID 4274083.
• Warn-Cramer BJ, Macrander LA, Abbott MT (1983). "Markedly different ascorbate dependencies of the sequential alpha-ketoglutarate dioxygenase reactions catalyzed by an essentially homogeneous thymine 7-hydroxylase from Rhodotorula glutinis". J. Biol. Chem. 258 (17): 10551–7. PMID 6684117.

This page was last edited on 26 August 2023, at 16:03