EC 1.14.13.101 - Senecionine N-oxygenase

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IntEnz Enzyme Nomenclature
EC 1.14.13.101

Names

Accepted name:
senecionine N-oxygenase
Other names:
senecionine monooxygenase (N-oxide-forming)
SNO
Systematic name:
senecionine,NADPH:oxygen oxidoreductase (N-oxide-forming)

Reaction

Cofactor

Comments:

A flavoprotein. NADH cannot replace NADPH. While pyrrolizidine alkaloids of the senecionine and monocrotaline types are generally good substrates (e.g. senecionine, retrorsine and monocrotaline), the enzyme does not use ester alkaloids lacking an hydroxy group at C-7 (e.g. supinine and phalaenopsine), 1,2-dihydro-alkaloids (e.g. sarracine) or unesterified necine bases (e.g. senkirkine) as substrates [1]. Senecionine N-oxide is used by insects as a chemical defense: senecionine N-oxide is non-toxic, but it is bioactivated to a toxic form by the action of cytochrome P450 oxidase when absorbed by insectivores.

Links to other databases

Enzymes and pathways: NC-IUBMB , BRENDA , ExplorEnz , ENZYME@ExPASy , KEGG , MetaCyc , UniPathway
Structural data: CSA , EC2PDB
Gene Ontology: GO:0033784
CAS Registry Number: 220581-68-0
UniProtKB/Swiss-Prot:

References

  1. Lindigkeit, R., Biller, A., Buch, M., Schiebel, H.M., Boppre, M. and Hartmann, T.
    The two facies of pyrrolizidine alkaloids: the role of the tertiary amine and its N-oxide in chemical defense of insects with acquired plant alkaloids.
    Eur. J. Biochem. 245: 626-636 (1997). [PMID: 9182998]
  2. Naumann, C., Hartmann, T. and Ober, D.
    Evolutionary recruitment of a flavin-dependent monooxygenase for the detoxification of host plant-acquired pyrrolizidine alkaloids in the alkaloid-defended arctiid moth Tyria jacobaeae.
    Proc. Natl. Acad. Sci. USA 99: 6085-6090 (2002). [PMID: 11972041]

[EC 1.14.13.101 created 2006]