KEGG   ENZYME: 1.14.13.117Help
Entry
EC 1.14.13.117              Enzyme                                 

Name
isoleucine N-monooxygenase;
CYP79D3;
CYP79D4
Class
Oxidoreductases;
Acting on paired donors, with incorporation or reduction of molecular oxygen;
With NADH or NADPH as one donor, and incorporation of one atom of oxygen into the other donor
BRITE hierarchy
Sysname
L-isoleucine,NADPH:oxygen oxidoreductase (N-hydroxylating)
Reaction(IUBMB)
L-isoleucine + 2 O2 + 2 NADPH + 2 H+ = (E)-2-methylbutanal oxime + 2 NADP+ + CO2 + 3 H2O (overall reaction) [RN:R09403];
(1a) L-isoleucine + O2 + NADPH + H+ = N-hydroxy-L-isoleucine + NADP+ + H2O [RN:R10027];
(1b) N-hydroxy-L-isoleucine + O2 + NADPH + H+ = N,N-dihydroxy-L-isoleucine + NADP+ + H2O [RN:R10028];
(1c) N,N-dihydroxy-L-isoleucine = (E)-2-methylbutanal oxime + CO2 + H2O (spontaneous) [RN:R10029]
Reaction(KEGG)
Substrate
L-isoleucine [CPD:C00407];
O2 [CPD:C00007];
NADPH [CPD:C00005];
H+ [CPD:C00080];
N-hydroxy-L-isoleucine [CPD:C20310];
N,N-dihydroxy-L-isoleucine [CPD:C20311]
Product
(E)-2-methylbutanal oxime [CPD:C19491];
NADP+ [CPD:C00006];
CO2 [CPD:C00011];
H2O [CPD:C00001];
N-hydroxy-L-isoleucine [CPD:C20310];
N,N-dihydroxy-L-isoleucine [CPD:C20311]
Comment
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 1.14.13.118 (valine N-monooxygenase), which prefers L-valine.
History
EC 1.14.13.117 created 2010
Pathway
Cyanoamino acid metabolism
Glucosinolate biosynthesis
Biosynthesis of secondary metabolites
Orthology
K14984  
isoleucine N-monooxygenase
Reference
1  [PMID:10636899]
  Authors
Andersen MD, Busk PK, Svendsen I, Moller BL
  Title
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.
  Journal
J. Biol. Chem. 275 (2000) 1966-75.
Reference
2  [PMID:15122013]
  Authors
Forslund K, Morant M, Jorgensen B, Olsen CE, Asamizu E, Sato S, Tabata S, Bak S
  Title
Biosynthesis of the nitrile glucosides rhodiocyanoside A and D and the cyanogenic glucosides lotaustralin and linamarin in Lotus japonicus.
  Journal
Plant. Physiol. 135 (2004) 71-84.
  Organism
Lotus japonicus
  Sequence
Other DBs
ExplorEnz - The Enzyme Database: 
IUBMB Enzyme Nomenclature: 
ExPASy - ENZYME nomenclature database: 
BRENDA, the Enzyme Database: 

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