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EC 1.17.99.3 Details

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EC number

1.17.99.3

Accepted name

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

Reaction

(25R)-3α,7α,12α-trihydroxy-5β-cholestan-26-oyl-CoA + H₂O + acceptor = (24R,25R)-3α,7α,12α,24-tetrahydroxy-5β-cholestan-26-oyl-CoA + reduced acceptor

Other name(s)

trihydroxycoprostanoyl-CoA oxidase, THC-CoA oxidase, THCA-CoA oxidase, 3α,7α,12α-trihydroxy-5β-cholestanoyl-CoA oxidase, 3α,7α,12α-trihydroxy-5β-cholestan-26-oate 24-hydroxylase

Systematic name

(25R)-3α,7α,12α-trihydroxy-5β-cholestan-26-oyl-CoA:acceptor 24-oxidoreductase (24R-hydroxylating)

CAS registry number

119799-47-2

Comment

Requires ATP. The reaction in mammals possibly involves dehydrogenation to give a 24(25)-double bond followed by hydration [1]. However, in amphibians such as the Oriental fire-bellied toad (Bombina orientalis), it is probable that the product is formed via direct hydroxylation of the saturated side chain of (25R)-3α,7α,12α-trihydroxy-5β-cholestan-26-oate and not via hydration of a 24(25) double bond [5]. In microsomes, the free acid is preferred to the coenzyme A ester, whereas in mitochondria, the coenzyme A ester is preferred to the free-acid form of the substrate [1].

History

created 2005

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)

1.6.4.1 created 1961, deleted 2002

1.6.4.2 created 1961, modified 1989, deleted 2002

1.6.4.3 created 1961, modified 1976, deleted 1983

1.6.4.4 created 1965, deleted 2002

1.6.4.5 created 1972, deleted 2002

1.6.4.6 created 1972, deleted 2002

1.6.4.7 created 1978, deleted 2002

1.6.4.8 created 1989, deleted 2002

1.6.4.9 created 1992, deleted 2002

1.6.4.10 created 1992, deleted 2002

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

1.11.1 Peroxidases

1.11.2 Peroxygenases

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

1.18 Acting on iron-sulfur proteins as donors

1.19 Acting on reduced flavodoxin as donor

1.20 Acting on phosphorus or arsenic in donors

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

1.21.1 With NAD⁺ or NADP⁺ as acceptor

1.21.3 With oxygen as acceptor

1.21.3.1 isopenicillin-N synthase

1.21.3.2 columbamine oxidase

1.21.3.3 reticuline oxidase

1.21.3.4 sulochrin oxidase [(+)-bisdechlorogeodin-forming]

1.21.3.5 sulochrin oxidase [(-)-bisdechlorogeodin-forming]

1.21.3.6 aureusidin synthase

1.21.3.7 tetrahydrocannabinolic acid synthase

1.21.3.8 cannabidiolic acid synthase

1.21.3.9 dichlorochromopyrrolate synthase

1.21.3.10 hercynylcysteine S-oxide synthase

1.21.4 With a disulfide as acceptor

1.21.98 With other, known, physiological acceptors

1.21.99 With unknown physiological acceptors

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)