CATH Classification

Domain Context

CATH Clusters

Superfamily Cytochrome P450
Functional Family Cytochrome P450 monooxygenase PikC

Enzyme Information
Cholest-4-en-3-one 26-monooxygenase ((25R)-3-oxocholest-4-en-26-oate forming).
based on mapping to UniProt P9WPP3
Cholest-4-en-3-one + 3 NADPH + 3 O(2) = (25R)-3-oxocholest-4-en-26-oate + 3 NADP(+) + 4 H(2)O.
-!- This enzyme, found in several bacterial pathogens, is involved in degradation of the host cholesterol. -!- It catalyzes 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. -!- The products are exclusively in the (25R) conformation. -!- The enzyme also accepts cholesterol as a substrate. -!- Cf. EC -!- The enzyme can receive electrons from ferredoxin reductase in vitro, its natural electron donor is not known yet.
Acting on paired donors, with incorporation or reduction of molecular oxygen. The oxygen incorporated need not be derived from O(2).
based on mapping to UniProt P9WPP3
Methyl-branched lipid omega-hydroxylase.
based on mapping to UniProt P9WPP3
A methyl-branched lipid + O(2) + 2 reduced ferredoxin [iron-sulfur] cluster + 2 H(+) = an omega-hydroxy-methyl-branched lipid + H(2)O + 2 oxidized ferredoxin [iron-sulfur] cluster.
-!- The enzyme, found in pathogenic and nonpathogenic mycobacteria species, actinomycetes, and some proteobacteria, hydroxylates the omega-carbon of a number of methyl-branched lipids, including (2E,6E)-farnesol, phytanate, geranylgeraniol, 15-methylpalmitate and (2E,6E)-farnesyl diphosphate.

UniProtKB Entries (1)

Mycobacterium tuberculosis H37Rv
Methyl-branched lipid omega-hydroxylase

PDB Structure

External Links
Primary Citation
Biochemical and structural characterization of CYP124: a methyl-branched lipid omega-hydroxylase from Mycobacterium tuberculosis.
Johnston, J.B., Kells, P.M., Podust, L.M., Ortiz de Montellano, P.R.
Proc. Natl. Acad. Sci. U.S.A.