EC Number   |
General Information |
Reference |
|---|
    1.14.11.31 | evolution |
the enzyme belongs to the 2-oxoglutarate/Fe(II)-dependent dioxygenase superfamily |
725537 |
| 1.14.11.31 | malfunction |
virus-induced gene silencing of T6ODM in opium poppy efficiently blocks metabolism at thebaine |
700357 |
| 1.14.11.31 | metabolism |
the enzyme-substrate complex of T6ODM has a 1:2 stoichiometry. The key residues responsible for substrate binding are Val128, Glu133, Met150 and Agr219 for the substrate in the distal position, and Asp144, Leu235 and Leu353 for the proximal substrate molecule. Tthe oxo ligand is bound trans to His295 and the enzyme catalyzes hydroxylation of the C6-bound methoxy group according to the established rebound mechanism. The final stage of the demethylation reaction includes deformylation and enol-keton tautomerization steps and is most likely catalyzed by water molecules and takes place in the solvent |
764879 |
| 1.14.11.31 | metabolism |
thebaine 6-O-demethylase catalyzes the antepenultimate step of morphine biosynthesis in opium poppy |
725537 |
| 1.14.11.31 | metabolism |
thebaine binds at the two distinct sites of T6ODM and codeine-3-O-demethylase CODM, EC 1.14.11.31, which determines the precise regioselectivity at C6 and C3 positions of thebaine respectively. Thebaine binds in site II (characteristic due to the presence of Asp313) of T6ODM for C6 selectivity. It binds in site I (characteristic due to the presence of Asp143) of CODM for C3 selectivity. Thebaine forms stable ionic interaction with these aspartate residues via its positively charged tertiary amino group and is further stabilized by the hydrophobic interactions via its B ring. The binding of oxygen to the nonheme iron is followed by the Fe(IV)=O bond flip, yielding an octahedral intermediate. During the decarboxylation reaction process, the C-terminal lid in the enzyme changes from the closed conformation in the 5C coordinate Fe(IV)=O complex to an active open conformation in the 6C coordinate complex |
764840 |
| 1.14.11.31 | physiological function |
thebaine 6-O-demethylase catalyzes the antepenultimate step of morphine biosynthesis in opium poppy, but has also roles in the metabolism of protopine, benzo[c]phenanthridine, and rhoeadine alkaloids |
725537 |
