Oxidoreductases;
Acting on paired donors, with incorporation or reduction of molecular oxygen;
With reduced flavin or flavoprotein as one donor, and incorporation of one atom of oxygen into the other donor
BRITE hierarchy

L-isoleucine,[reduced NADPH---hemoprotein reductase]:oxygen oxidoreductase (N-hydroxylating)

L-isoleucine + 2 [reduced NADPH---hemoprotein reductase] + 2 O2 = (1E,2S)-2-methylbutanal oxime + 2 [oxidized NADPH---hemoprotein reductase] + CO2 + 3 H2O (overall reaction) [RN:R09403];
(1a) L-isoleucine + [reduced NADPH---hemoprotein reductase] + O2 = N-hydroxy-L-isoleucine + [oxidized NADPH---hemoprotein reductase] + H2O [RN:R10027];
(1b) N-hydroxy-L-isoleucine + [reduced NADPH---hemoprotein reductase] + O2 = N,N-dihydroxy-L-isoleucine + [oxidized NADPH---hemoprotein reductase] + H2O [RN:R10028];
(1c) N,N-dihydroxy-L-isoleucine = (1E,2S)-2-methylbutanal oxime + CO2 + H2O (spontaneous) [RN:R10029]

R09403 R10027 R10028 R10029;
(other) R10031 R10032 R10033
Reaction

L-isoleucine [CPD:C00407];
[reduced NADPH---hemoprotein reductase] [CPD:C03024];
O2 [CPD:C00007];
N-hydroxy-L-isoleucine [CPD:C20310];
N,N-dihydroxy-L-isoleucine [CPD:C20311]

This cytochrome P-450 (heme-thiolate) enzyme, found in plants, catalyses two successive N-hydroxylations of L-isoleucine, the committed step in the biosynthesis of the cyanogenic glucoside lotaustralin. The product of the two hydroxylations, N,N-dihydroxy-L-isoleucine, is labile and undergoes dehydration followed by decarboxylation, producing the oxime. It is still not known whether the decarboxylation is spontaneous or catalysed by the enzyme. The enzyme can also accept L-valine, but with a lower activity. cf. EC 1.14.14.38, valine N-monooxygenase.

EC 1.14.14.39 created 2010 as EC 1.14.13.117, transferred 2017 to EC 1.14.14.39

1  [PMID:10636899]

2  [PMID:15122013]