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EC 1.14.15.6 Details

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EC number

1.14.15.6

Accepted name

cholesterol monooxygenase (side-chain-cleaving)

Reaction

cholesterol + 6 reduced adrenodoxin + 3 O₂ + 6 H⁺ = pregnenolone + 4-methylpentanal + 6 oxidized adrenodoxin + 4 H₂O (overall reaction);;(1a) cholesterol + 2 reduced adrenodoxin + O₂ + 2 H⁺ = (22R)-22-hydroxycholesterol + 2 oxidized adrenodoxin + H₂O;;(1b) (22R)-22-hydroxycholesterol + 2 reduced adrenodoxin + O₂ + 2 H⁺ = (20R,22R)-20,22-dihydroxycholesterol + 2 oxidized adrenodoxin + H₂O;;(1c) (20R,22R)-20,22-dihydroxy-cholesterol + 2 reduced adrenodoxin + O₂ + 2 H⁺ = pregnenolone + 4-methylpentanal + 2 oxidized adrenodoxin + 2 H₂O

Other name(s)

cholesterol desmolase, cytochrome P-450_scc, C₂₇-side chain cleavage enzyme, cholesterol 20-22-desmolase, cholesterol C_20-22 desmolase, cholesterol side-chain cleavage enzyme, cholesterol side-chain-cleaving enzyme, steroid 20-22 desmolase, steroid 20-22-lyase, CYP11A1 (gene name)

Systematic name

cholesterol,reduced-adrenodoxin:oxygen oxidoreductase (side-chain-cleaving)

CAS registry number

37292-81-2, 440354-98-3

Comment

A heme-thiolate protein (cytochrome P-450). The reaction proceeds in three stages, with two hydroxylations at C-22 and C-20 preceding scission of the side-chain between carbons 20 and 22. The initial source of the electrons is NADPH, which transfers the electrons to the adrenodoxin via EC 1.18.1.6, adrenodoxin-NADP⁺ reductase.

History

created 1983, modified 2013, modified 2014

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)

1.6.7.1 created 1972, deleted 1978

1.6.7.2 created 1972, deleted 1978

1.6.7.3 created 1978, deleted 1978

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

1.14.1 With NADH or NADPH as one donor (deleted sub-subclass)

1.14.2 With ascorbate as one donor (deleted sub-subclass)

1.14.3 With reduced pteridine as one donor (deleted sub-subclass)

1.14.11 With 2-oxoglutarate as one donor, and incorporation of one atom of oxygen into each donor

1.14.12 With NADH or NADPH as one donor, and incorporation of two atoms of oxygen into the other donor

1.14.13 With NADH or NADPH as one donor, and incorporation of one atom of oxygen into the other donor

1.14.14 With reduced flavin or flavoprotein as one donor, and incorporation of one atom of oxygen into the other donor

1.14.15 With reduced iron-sulfur protein as one donor, and incorporation of one atom of oxygen into the other donor

1.14.15.1 camphor 5-monooxygenase

1.14.15.2 camphor 1,2-monooxygenase

1.14.15.3 alkane 1-monooxygenase

1.14.15.4 steroid 11β-monooxygenase

1.14.15.5 corticosterone 18-monooxygenase

1.14.15.6 cholesterol monooxygenase (side-chain-cleaving)

1.14.15.7 choline monooxygenase

1.14.15.8 steroid 15β-monooxygenase

1.14.15.9 spheroidene monooxygenase

1.14.15.10 (+)-camphor 6-endo-hydroxylase

1.14.15.11 pentalenic acid synthase

1.14.15.12 pimeloyl-[acyl-carrier protein] synthase

1.14.15.13 pulcherriminic acid synthase

1.14.15.14 methyl-branched lipid ω-hydroxylase

1.14.15.15 cholestanetriol 26-monooxygenase

1.14.15.16 vitamin D₃ 24-hydroxylase

1.14.15.17 pheophorbide a oxygenase

1.14.15.18 calcidiol 1-monooxygenase

1.14.15.19 C-19 steroid 1α-hydroxylase

1.14.15.20 heme oxygenase (biliverdin-producing, ferredoxin)

1.14.15.21 zeaxanthin epoxidase

1.14.15.22 vitamin D 1,25-hydroxylase

1.14.15.23 chloroacetanilide N-alkylformylase

1.14.15.24 β-carotene 3-hydroxylase

1.14.15.25 p-cymene methyl-monooxygenase

1.14.15.26 toluene methyl-monooxygenase

1.14.15.27 β-dihydromenaquinone-9 ω-hydroxylase

1.14.15.28 cholest-4-en-3-one 26-monooxygenase [(25R)-3-oxocholest-4-en-26-oate forming]

1.14.15.29 cholest-4-en-3-one 26-monooxygenase [(25S)-3-oxocholest-4-en-26-oate forming]

1.14.15.30 3-ketosteroid 9α-monooxygenase

1.14.15.31 2-hydroxy-5-methyl-1-naphthoate 7-hydroxylase

1.14.15.32 pentalenene oxygenase

1.14.15.33 pikromycin synthase

1.14.15.34 20-oxo-5-O-mycaminosyltylactone 23-monooxygenase

1.14.15.35 6-deoxyerythronolide B hydroxylase

1.14.15.36 sterol 14α-demethylase (ferredoxin)

1.14.15.37 luteothin monooxygenase

1.14.15.38 N,N-dimethyl phenylurea N-demethylase

1.14.15.39 epi-isozizaene 5-monooxygenase

1.14.16 With reduced pteridine as one donor, and incorporation of one atom of oxygen into the other donor

1.14.17 With reduced ascorbate as one donor, and incorporation of one atom of oxygen into the other donor

1.14.18 With another compound as one donor, and incorporation of one atom of oxygen into the other donor

1.14.19 With oxidation of a pair of donors resulting in the reduction of O₂ to two molecules of water

1.14.20 With 2-oxoglutarate as one donor, and the other dehydrogenated

1.14.21 With NADH or NADPH as one donor, and the other dehydrogenated

1.14.99 Miscellaneous

1.14.99.1 prostaglandin-endoperoxide synthase

1.14.99.2 kynurenine 7,8-hydroxylase

1.14.99.3 heme oxygenase (biliverdin-producing)

1.14.99.4 progesterone monooxygenase

1.14.99.5 created 1972, modified 1986, modified 2000, deleted 2000

1.14.99.6 created 1972, modified 2000, deleted 2000

1.14.99.7 squalene monooxygenase

1.14.99.8 created 1972, deleted 1984

1.14.99.9 steroid 17α-monooxygenase

1.14.99.10 steroid 21-monooxygenase

1.14.99.11 estradiol 6β-monooxygenase

1.14.99.12 androst-4-ene-3,17-dione monooxygenase

1.14.99.13 created 1972, deleted 1984

1.14.99.14 progesterone 11α-monooxygenase

1.14.99.15 4-methoxybenzoate monooxygenase (O-demethylating)

1.14.99.16 created 1972, deleted 2002

1.14.99.17 created 1972, deleted 1976

1.14.99.18 created 1976, modified 1999, deleted 2003

1.14.99.19 plasmanylethanolamine desaturase

1.14.99.20 phylloquinone monooxygenase (2,3-epoxidizing)

1.14.99.21 Latia-luciferin monooxygenase (demethylating)

1.14.99.22 ecdysone 20-monooxygenase

1.14.99.23 3-hydroxybenzoate 2-monooxygenase

1.14.99.24 steroid 9α-monooxygenase

1.14.99.25 created 1986, deleted 2000

1.14.99.26 2-hydroxypyridine 5-monooxygenase

1.14.99.27 juglone 3-monooxygenase

1.14.99.28 linalool 8-monooxygenase

1.14.99.29 deoxyhypusine monooxygenase

1.14.99.30 carotene 7,8-desaturase

1.14.99.31 myristoyl-CoA 11-(E) desaturase

1.14.99.32 myristoyl-CoA 11-(Z) desaturase

1.14.99.33 Δ¹²-fatty acid dehydrogenase

1.14.99.34 monoprenyl isoflavone epoxidase

1.14.99.35 thiophene-2-carbonyl-CoA monooxygenase

1.14.99.36 β-carotene 15,15′-monooxygenase

1.14.99.37 taxadiene 5α-hydroxylase

1.14.99.38 cholesterol 25-monooxygenase

1.14.99.39 ammonia monooxygenase

1.14.99.40 5,6-dimethylbenzimidazole synthase

1.14.99.41 all-trans-8′-apo-β-carotenal 15,15′-oxygenase

1.14.99.42 zeaxanthin 7,8-dioxygenase

1.14.99.43 β-amyrin 24-hydroxylase

1.14.99.44 diapolycopene oxygenase

1.14.99.45 carotene ε-monooxygenase

1.14.99.46 pyrimidine oxygenase

1.14.99.47 (+)-larreatricin hydroxylase

1.14.99.48 heme oxygenase (staphylobilin-producing)

1.14.99.49 2-hydroxy-5-methyl-1-naphthoate 7-hydroxylase

1.14.99.50 γ-glutamyl hercynylcysteine S-oxide synthase

1.14.99.51 hercynylcysteine S-oxide synthase

1.14.99.52 L-cysteinyl-L-histidinylsulfoxide synthase

1.14.99.53 lytic chitin monooxygenase

1.14.99.54 lytic cellulose monooxygenase (C1-hydroxylating)

1.14.99.55 lytic starch monooxygenase

1.14.99.56 lytic cellulose monooxygenase (C4-dehydrogenating)

1.14.99.57 heme oxygenase (mycobilin-producing)

1.14.99.58 heme oxygenase (biliverdin-IX-β and δ-forming)

1.14.99.59 tryptamine 4-monooxygenase

1.14.99.60 3-demethoxyubiquinol 3-hydroxylase

1.14.99.61 cyclooctat-9-en-7-ol 5-monooxygenase

1.14.99.62 cyclooctatin synthase

1.14.99.63 β-carotene 4-ketolase

1.14.99.64 zeaxanthin 4-ketolase

1.14.99.65 4-amino-L-phenylalanyl-[CmlP-peptidyl-carrier-protein] 3-hydroxylase

1.14.99.66 [histone H3]-N⁶,N⁶-dimethyl-L-lysine⁴ FAD-dependent demethylase

1.14.99.67 α-N-dichloroacetyl-p-aminophenylserinol N-oxygenase

1.14.99.68 4-aminobenzoate N-oxygenase

1.14.99.69 tRNA 2-(methylsulfanyl)-N⁶-isopentenyladenosine³⁷ hydroxylase

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

1.21.4 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

1.97.1 Sole sub-subclass for oxidoreductases that do not belong in the other subclasses

1.98 Enzymes using H₂ as reductant (deleted subclass)

1.99 Other enzymes using O₂ as oxidant (deleted subclass)

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Release 2023.1 (January 2023)