1.14.13.246: 4beta-methylsterol monooxygenase
This is an abbreviated version!
For detailed information about 4beta-methylsterol monooxygenase, go to the full flat file.
Reaction
Synonyms
SdmA
ECTree
1.14.13.246 4beta-methylsterol monooxygenaseAdvanced search results
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| 1 | AA Sequence |
| 1 | Cofactor |
| 2 | General Information |
| 2 | Natural Substrates/ Products (Substrates) |
| 2 | Organism |
| 1 | Pathway |
| 4 | Reaction |
| 2 | Reference |
| 7 | Substrates and Products (Substrate) |
| 3 | Synonyms |
| 1 | Systematic Name |
Systematic Name
Systematic Name on EC 1.14.13.246 - 4beta-methylsterol monooxygenase
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SYSTEMATIC NAME 
IUBMB Comments
3beta-hydroxy-4,4-dimethylsteroid,NADH:oxygen oxidoreductase (C-4mbeta-hydroxylating)
Contains a Rieske [2Fe-2S] iron-sulfur cluster. This bacterial enzyme (SdmA) participates in the biosynthesis of bacterial sterols. Together with SdmB it forms an enzyme system that removes one methyl group from the C-4 position of 4,4-dimethylated steroid molecules. SdmA catalyses three successive oxidations of the C-4beta methyl group, turning it into a carboxylate group; the second enzyme, SdmB, is a bifunctional enzyme that catalyses two different activities. As EC 1.1.1.417, 3beta-hydroxysteroid-4beta-carboxylate 3-dehydrogenase (decarboxylating), it catalyses an oxidative decarboxylation that results in reduction of the 3beta-hydroxy group at the C-3 carbon to an oxo group. As EC 1.1.1.270, 3beta-hydroxysteroid 3-dehydrogenase, it reduces the 3-oxo group back to a 3beta-hydroxyl. Unlike the animal/fungal enzyme EC 1.14.18.9, 4alpha-methylsterol monooxygenase, and the plant enzymes EC 1.14.18.10, plant 4,4-dimethylsterol C-4alpha-methyl-monooxygenase, and EC 1.14.18.11, plant 4alpha-monomethylsterol monooxygenase, this enzyme acts preferentially on the 4beta-methyl group. Since no epimerization of the remaining C-4alpha methyl group occurs, the enzyme can only remove one methyl group, leaving a 4alpha-monomethylated product. Known substrates include 4,4-dimethyl-5alpha-cholest-8-en-3beta-ol and 14-demethyllanosterol.
