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EC 1.17.99.4 Details

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EC number

1.17.99.4

Accepted name

uracil/thymine dehydrogenase

Reaction

(1) uracil + H₂O + acceptor = barbiturate + reduced acceptor;;(2) thymine + H₂O + acceptor = 5-methylbarbiturate + reduced acceptor

Other name(s)

uracil oxidase, uracil-thymine oxidase, uracil dehydrogenase

Systematic name

uracil:acceptor oxidoreductase

CAS registry number

9029-00-9

Comment

Forms part of the oxidative pyrimidine-degrading pathway in some microorganisms, along with EC 3.5.2.1 (barbiturase) and EC 3.5.1.95 (N-malonylurea hydrolase). Mammals, plants and other microorganisms utilize the reductive pathway, comprising EC 1.3.1.1 [dihydrouracil dehydrogenase (NAD⁺)] or EC 1.3.1.2 [dihydropyrimidine dehydrogenase (NADP⁺)], EC 3.5.2.2 (dihydropyrimidinase) and EC 3.5.1.6 (β-ureidopropionase), with the ultimate degradation products being an L-amino acid, NH₃ and CO₂ [5].

History

created 1961 as EC 1.2.99.1, transferred 1984 to EC 1.1.99.19, transferred 2006 to EC 1.17.99.4

EC Tree

1 Oxidoreductases

1.1 Acting on the CH-OH group of donors

1.2 Acting on the aldehyde or oxo group of donors

1.3 Acting on the CH-CH group of donors

1.4 Acting on the CH-NH₂ group of donors

1.5 Acting on the CH-NH group of donors

1.6 Acting on NADH or NADPH

1.6.1 With NAD⁺ or NADP⁺ as acceptor

1.6.2 With a heme protein as acceptor

1.6.3 With oxygen as acceptor

1.6.4 With a disulfide as acceptor (deleted sub-subclass)

1.6.5 With a quinone or similar compound as acceptor

1.6.6 With a nitrogenous group as acceptor

1.6.7 With an iron-sulfur protein as acceptor (deleted sub-subclass)

1.6.8 With a flavin as acceptor (deleted sub-subclass)

1.6.99 With unknown physiological acceptors

1.7 Acting on other nitrogenous compounds as donors

1.8 Acting on a sulfur group of donors

1.9 Acting on a heme group of donors

1.10 Acting on diphenols and related substances as donors

1.11 Acting on a peroxide as acceptor

1.12 Acting on hydrogen as donor

1.13 Acting on single donors with incorporation of molecular oxygen (oxygenases)

1.14 Acting on paired donors, with incorporation or reduction of molecular oxygen

1.15 Acting on superoxide as acceptor

1.16 Oxidizing metal ions

1.17 Acting on CH or CH₂ groups

1.17.1 With NAD⁺ or NADP⁺ as acceptor

1.17.2 With a cytochrome as acceptor

1.17.3 With oxygen as acceptor

1.17.4 With a disulfide as acceptor

1.17.5 With a quinone or similar compound as acceptor

1.17.7 With an iron-sulfur protein as acceptor

1.17.8 With a flavin as acceptor

1.17.9 With a copper protein as acceptor

1.17.98 With other, known, physiological acceptors

1.17.99 With unknown physiological acceptors

1.17.99.1 4-methylphenol dehydrogenase (hydroxylating)

1.17.99.2 ethylbenzene hydroxylase

1.17.99.3 3α,7α,12α-trihydroxy-5β-cholestanoyl-CoA 24-hydroxylase

1.17.99.4 uracil/thymine dehydrogenase

1.17.99.5 bile-acid 7α-dehydroxylase

1.17.99.6 epoxyqueuosine reductase

1.17.99.7 formate dehydrogenase (acceptor)

1.17.99.8 limonene dehydrogenase

1.17.99.9 heme a synthase

1.17.99.10 steroid C-25 hydroxylase

1.17.99.11 3-oxo-Δ¹-steroid hydratase/dehydrogenase

1.18 Acting on iron-sulfur proteins as donors

1.19 Acting on reduced flavodoxin as donor

1.20 Acting on phosphorus or arsenic in donors

1.20.1 With NAD⁺ or NADP⁺ as acceptor

1.20.2 With a cytochrome as acceptor

1.20.4 With disulfide as acceptor

1.20.9 With a copper protein as acceptor

1.20.98 With other, known, physiological acceptors

1.20.99 With unknown physiological acceptors

1.21 Catalysing the reaction X-H + Y-H = X-Y

1.22 Acting on halogen in donors

1.23 Reducing C-O-C group as acceptor

1.97 Other oxidoreductases

1.98 Enzymes using H₂ as reductant (deleted subclass)

1.99 Other enzymes using O₂ as oxidant (deleted subclass)