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EC 1.14.13.141 Details
show Brenda entryEC number
1.14.13.141
Accepted name
cholest-4-en-3-one 26-monooxygenase [(25S)-3-oxocholest-4-en-26-oate forming]
Reaction
cholest-4-en-3-one + 3 NADH + 3 H+ + 3 O2 = (25S)-3-oxocholest-4-en-26-oate + 3 NAD+ + 4 H2O (overall reaction);;(1a) cholest-4-en-3-one + NADH + H+ + O2 = (25S)-26-hydroxycholest-4-en-3-one + NAD+ + H2O;;(1b) (25S)-26-hydroxycholest-4-en-3-one + NADH + H+ + O2 = (25S)-26-oxocholest-4-en-3-one + NAD+ + 2 H2O;;(1c) (25S)-26-oxocholest-4-en-3-one + NADH + H+ + O2 = (25S)-3-oxocholest-4-en-26-oate + NAD+ + H2O;;
Other name(s)
CYP125,
CYP125A1,
cholest-4-en-3-one 27-monooxygenase (misleading),
cholest-4-en-3-one,NADH:oxygen oxidoreductase (26-hydroxylating),
cholest-4-en-3-one 26-monooxygenase (ambiguous)
Systematic name
cholest-4-en-3-one,NADH:oxygen oxidoreductase [(25S)-3-oxocholest-4-en-26-oate forming]
Comment
This enzyme, found in several bacterial pathogens, is involved in degradation of the host’s cholesterol. It catalyses the hydroxylation of the C-26 carbon, followed by oxidation of the alcohol to the carboxylic acid via the aldehyde intermediate, initiating the degradation of the alkyl side-chain of cholesterol [4]. The products are exclusively in the (25S) configuration. It is a two-component system consisting of a P-450 (heme thiolate) oxygenase (Cyp125) and a ferredoxin reductase (most likely KshB, which is also a part of EC 1.14.13.142, 3-ketosteroid 9α-monooxygenase). The enzyme also accepts cholesterol as a substrate. cf. EC 1.14.15.28, cholest-4-en-3-one 26-monooxygenase [(25R)-3-oxocholest-4-en-26-oate forming].
History
created 2012, modified 2016, deleted 2018
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1 Oxidoreductases
1.1 Acting on the CH-OH group of donors
1.14.13.45 created 1992, deleted 2003
