The Enzyme Database

Your query returned 1 entry.    printer_iconPrintable version

Accepted name: isoleucine N-monooxygenase
Reaction: L-isoleucine + 2 O2 + 2 NADPH + 2 H+ = (E)-2-methylbutanal oxime + 2 NADP+ + CO2 + 3 H2O (overall reaction)
(1a) L-isoleucine + O2 + NADPH + H+ = N-hydroxy-L-isoleucine + NADP+ + H2O
(1b) N-hydroxy-L-isoleucine + O2 + NADPH + H+ = N,N-dihydroxy-L-isoleucine + NADP+ + H2O
(1c) N,N-dihydroxy-L-isoleucine = (E)-2-methylbutanal oxime + CO2 + H2O (spontaneous)
Other name(s): CYP79D3; CYP79D4
Systematic name: L-isoleucine,NADPH:oxygen oxidoreductase (N-hydroxylating)
Comments: A heme-thiolate protein (P-450). This enzyme catalyses two successive N-hydroxylations of L-isoleucine, the first committed steps in the biosynthesis of the cyanogenic glucoside lotaustralin in the plant Lotus japonicus. The product of the two hydroxylations, N,N-dihydroxy-L-isoleucine, is extremely labile and dehydrates spontaneously. The dehydrated product is then subject to a decarboxylation that produces the oxime. It is still not known whether the decarboxylation is spontaneous or catalysed by the enzyme. The product, (E)-2-methylbutanal oxime, undergoes a spontaneous isomerization to the (Z) form. The enzyme can also accept L-valine as substrate, with a lower activity. It is different from EC (valine N-monooxygenase), which prefers L-valine.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc
1.  Andersen, M.D., Busk, P.K., Svendsen, I. and Møller, B.L. Cytochromes P-450 from cassava (Manihot esculenta Crantz) catalyzing the first steps in the biosynthesis of the cyanogenic glucosides linamarin and lotaustralin. Cloning, functional expression in Pichia pastoris, and substrate specificity of the isolated recombinant enzymes. J. Biol. Chem. 275 (2000) 1966–1975. [PMID: 10636899]
2.  Forslund, K., Morant, M., Jørgensen, B., Olsen, C.E., Asamizu, E., Sato, S., Tabata, S. and Bak, S. Biosynthesis of the nitrile glucosides rhodiocyanoside A and D and the cyanogenic glucosides lotaustralin and linamarin in Lotus japonicus. Plant Physiol. 135 (2004) 71–84. [PMID: 15122013]
[EC created 2010]

Data © 2001–2017 IUBMB
Web site © 2005–2017 Andrew McDonald