Methylsterol monooxygenase

Methylsterol monooxygenase (EC 1.14.13.72, methylsterol hydroxylase, 4-methylsterol oxidase, 4,4-dimethyl-5alpha-cholest-7-en-3beta-ol,hydrogen-donor:oxygen oxidoreductase (hydroxylating)) is an enzyme with systematic name 4,4-dimethyl-5alpha-cholest-7-en-3beta-ol,NAD(P)H:oxygen oxidoreductase (hydroxylating).^{[1][2][3][4][5][6][7]} This enzyme catalyses the following chemical reaction

4,4-dimethyl-5alpha-cholest-7-en-3beta-ol + 3 NAD(P)H + 3 H⁺ + 3 O₂ ${\displaystyle \rightleftharpoons }$ 3beta-hydroxy-4beta-methyl-5alpha-cholest-7-ene-4alpha-carboxylate + 3 NAD(P)⁺ + 4 H₂O (overall reaction)

(1a) 4,4-dimethyl-5alpha-cholest-7-en-3beta-ol + NAD(P)H + H⁺ + O₂ ${\displaystyle \rightleftharpoons }$ 4beta-hydroxymethyl-4alpha-methyl-5alpha-cholest-7-en-3beta-ol + NAD(P)⁺ + H₂O

(1b) 4beta-hydroxymethyl-4alpha-methyl-5alpha-cholest-7-en-3beta-ol + NAD(P)H + H⁺ + O₂ ${\displaystyle \rightleftharpoons }$ 3beta-hydroxy-4beta-methyl-5alpha-cholest-7-ene-4alpha-carbaldehyde + NAD(P)⁺ + 2 H₂O

(1c) 3beta-hydroxy-4beta-methyl-5alpha-cholest-7-ene-4alpha-carbaldehyde + NAD(P)H + H⁺ + O₂ ${\displaystyle \rightleftharpoons }$ 3beta-hydroxy-4beta-methyl-5alpha-cholest-7-ene-4alpha-carboxylate + NAD(P)⁺ + H₂O

Methylsterol monooxygenase
Identifiers
EC no.	1.14.13.72
CAS no.	37256-80-7
Databases
IntEnz	IntEnz view
BRENDA	BRENDA entry
ExPASy	NiceZyme view
KEGG	KEGG entry
MetaCyc	metabolic pathway
PRIAM	profile
PDB structures	RCSB PDB PDBe PDBsum
Search PMC articles PubMed articles NCBI proteins

Methylsterol monooxygenase requires cytochrome b5.