Details

Autor(en) / Beteiligte

• Hansen, C H
• Du, L
• Naur, P
• Olsen, C E
• Axelsen, K B
• Hick, A J
• Pickett, J A
• Halkier, B A

Titel

CYP83B1 Is the Oxime-metabolizing Enzyme in the Glucosinolate Pathway in Arabidopsis

Ist Teil von

• The Journal of biological chemistry, 2001-07, Vol.276 (27), p.24790-24796

Ort / Verlag

United States: American Society for Biochemistry and Molecular Biology

Erscheinungsjahr

2001

Quelle

MEDLINE

Beschreibungen/Notizen

• CYP83B1 from Arabidopsis thaliana has been identified as the oxime-metabolizing enzyme in the biosynthetic pathway of glucosinolates. Biosynthetically active microsomes isolated from Sinapis alba converted p -hydroxyphenylacetaldoxime and cysteine into S -alkylated p -hydroxyphenylacetothiohydroximate, S -( p -hydroxyphenylacetohydroximoyl)- l -cysteine, the next proposed intermediate in the glucosinolate pathway. The production was shown to be dependent on a cytochrome P450 monooxygenase. We searched the genome of A. thaliana for homologues of CYP71E1 (P450ox), the only known oxime-metabolizing enzyme in the biosynthetic pathway of the evolutionarily related cyanogenic glucosides. By a combined use of bioinformatics, published expression data, and knock-out phenotypes, we identified the cytochrome P450 CYP83B1 as the oxime-metabolizing enzyme in the glucosinolate pathway as evidenced by characterization of the recombinant protein expressed in Escherichia coli . The data are consistent with the hypothesis that the oxime-metabolizing enzyme in the cyanogenic pathway (P450ox) was mutated into a “P450 m ox” that converted oximes into toxic compounds that the plant detoxified into glucosinolates.