KEGG   ENZYME: 1.14.13.118Help
Entry
EC 1.14.13.118              Enzyme                                 

Name
valine N-monooxygenase;
CYP79D1;
CYP79D2
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-valine,NADPH:oxygen oxidoreductase (N-hydroxylating)
Reaction(IUBMB)
L-valine + 2 O2 + 2 NADPH + 2 H+ = (E)-2-methylpropanal oxime + 2 NADP+ + CO2 + 3 H2O (overall reaction) [RN:R08663];
(1a) L-valine + O2 + NADPH + H+ = N-hydroxy-L-valine + NADP+ + H2O [RN:R10031];
(1b) N-hydroxy-L-valine + O2 + NADPH + H+ = N,N-dihydroxy-L-valine + NADP+ + H2O [RN:R10032];
(1c) N,N-dihydroxy-L-valine = (E)-2-methylpropanal oxime + CO2 + H2O (spontaneous) [RN:R10033]
Reaction(KEGG)
Substrate
L-valine [CPD:C00183];
O2 [CPD:C00007];
NADPH [CPD:C00005];
H+ [CPD:C00080];
N-hydroxy-L-valine [CPD:C20313];
N,N-dihydroxy-L-valine [CPD:C20314]
Product
(E)-2-methylpropanal oxime [CPD:C03219];
NADP+ [CPD:C00006];
CO2 [CPD:C00011];
H2O [CPD:C00001];
N-hydroxy-L-valine [CPD:C20313];
N,N-dihydroxy-L-valine [CPD:C20314]
Comment
A heme-thiolate protein (P-450). This enzyme catalyses two successive N-hydroxylations of L-valine, the first committed steps in the biosynthesis of the cyanogenic glucoside linamarin in Manihot esculenta (cassava). The product of the two hydroxylations, N,N-dihydroxy-L-valine, 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-methylpropanal oxime, undergoes a spontaneous isomerization to the (Z) form. The enzyme can also accept L-isoleucine as substrate, with a lower activity. It is different from EC 1.14.13.117 (isoleucine N-monooxygenase), which prefers L-isoleucine.
History
EC 1.14.13.118 created 2010
Pathway
Cyanoamino acid metabolism
Glucosinolate biosynthesis
Biosynthesis of secondary metabolites
Orthology
K13401  
valine 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.
  Sequence
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.
Other DBs
ExplorEnz - The Enzyme Database: 
IUBMB Enzyme Nomenclature: 
ExPASy - ENZYME nomenclature database: 
BRENDA, the Enzyme Database: 

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