ExplorEnz: Search Results

Your query returned 3 entries. Printable version

1.14.14.42

Accepted name:

homomethionine N-monooxygenase

Reaction:

an L-polyhomomethionine + 2 [reduced NADPH—hemoprotein reductase] + 2 O₂ = an (E)-ω-(methylsulfanyl)alkanal oxime + 2 [oxidized NADPH—hemoprotein reductase] + CO₂ + 3 H₂O (overall reaction)
(1a) an L-polyhomomethionine + [reduced NADPH—hemoprotein reductase] + O₂ = an L-N-hydroxypolyhomomethionine + [oxidized NADPH—hemoprotein reductase] + H₂O
(1b) an L-N-hydroxypolyhomomethionine + [reduced NADPH—hemoprotein reductase] + O₂ = an L-N,N-dihydroxypolyhomomethionine + [oxidized NADPH—hemoprotein reductase] + H₂O
(1c) an L-N,N-dihydroxypolyhomomethionine = an (E)-ω-(methylsulfanyl)alkanal oxime + CO₂ + H₂O

Glossary:

homomethionine = (2S)-2-amino-5-(methylsulfanyl)pentanoate
an L-polyhomomethionine = analogs of L-methionine that contain additional methylene groups in the side chain prior to the sulfur atom.

Other name(s):

CYP79F1 (gene name); CYP79F2 (gene name)

Systematic name:

L-polyhomomethionine,[NADPH—hemoprotein reductase]:oxygen oxidoreductase

Comments:

This plant cytochrome P-450 (heme thiolate) enzyme is involved in methionine-derived aliphatic glucosinolates biosynthesis. It catalyses two successive N-hydroxylations, which are followed by dehydration and decarboxylation. CYP79F1 from Arabidopsis thaliana can metabolize mono-, di-, tri-, tetra-, penta-, and hexahomomethionine to their corresponding aldoximes, while CYP79F2 from the same plant can only metabolize penta- and hexahomomethionine.

Links to other databases:

BRENDA, EXPASY, KEGG, MetaCyc

References:

1.	Hansen, C.H., Wittstock, U., Olsen, C.E., Hick, A.J., Pickett, J.A. and Halkier, B.A. Cytochrome p₄₅₀ CYP79F1 from arabidopsis catalyzes the conversion of dihomomethionine and trihomomethionine to the corresponding aldoximes in the biosynthesis of aliphatic glucosinolates. J. Biol. Chem. 276 (2001) 11078–11085. [DOI] [PMID: 11133994]
2.	Chen, S., Glawischnig, E., Jørgensen, K., Naur, P., Jorgensen, B., Olsen, C.E., Hansen, C.H., Rasmussen, H., Pickett, J.A. and Halkier, B.A. CYP79F1 and CYP79F2 have distinct functions in the biosynthesis of aliphatic glucosinolates in Arabidopsis. Plant J. 33 (2003) 923–937. [DOI] [PMID: 12609033]

[EC 1.14.14.42 created 2017]

2.3.3.17

Accepted name:

methylthioalkylmalate synthase

Reaction:

an ω-(methylsulfanyl)-2-oxoalkanoate + acetyl-CoA + H₂O = a 2-[ω-(methylsulfanyl)alkyl]malate + CoA

For diagram of L-Homomethionine biosynthesis, click here

Other name(s):

MAM1 (gene name); MAM3 (gene name); acetyl-CoA:ω-(methylthio)-2-oxoalkanoate C-acetyltransferase

Systematic name:

acetyl-CoA:ω-(methylsulfanyl)-2-oxoalkanoate C-acetyltransferase

Comments:

The enzyme, characterized from the plant Arabidopsis thaliana, is involved in the L-methionine side-chain elongation pathway, forming substrates for the biosynthesis of aliphatic glucosinolates. Two forms are known - MAM1 catalyses only only the first two rounds of methionine chain elongation, while MAM3 catalyses all six cycles, up to formation of L-hexahomomethionine.

Links to other databases:

BRENDA, EXPASY, KEGG, MetaCyc

References:

1.	Textor, S., Bartram, S., Kroymann, J., Falk, K.L., Hick, A., Pickett, J.A. and Gershenzon, J. Biosynthesis of methionine-derived glucosinolates in Arabidopsis thaliana: recombinant expression and characterization of methylthioalkylmalate synthase, the condensing enzyme of the chain-elongation cycle. Planta 218 (2004) 1026–1035. [DOI] [PMID: 14740211]
2.	Textor, S., de Kraker, J.W., Hause, B., Gershenzon, J. and Tokuhisa, J.G. MAM3 catalyzes the formation of all aliphatic glucosinolate chain lengths in Arabidopsis. Plant Physiol. 144 (2007) 60–71. [DOI] [PMID: 17369439]

[EC 2.3.3.17 created 2016]

4.2.1.170

Accepted name:

2-(ω-methylthio)alkylmalate dehydratase

Reaction:

(1) a 2-[(ω-methylsulfanyl)alkyl]malate = a 2-[(ω-methylsulfanyl)alkyl]maleate + H₂O
(2) a 3-[(ω-methylsulfanyl)alkyl]malate = a 2-[(ω-methylsulfanyl)alkyl]maleate + H₂O

For diagram of L-Homomethionine biosynthesis, click here

Other name(s):

IPMI (gene name); 2-[(ω-methylthio)alkyl]malate hydro-lyase (2-[(ω-methylthio)alkyl]maleate-forming)

Systematic name:

2-[(ω-methylsulfanyl)alkyl]malate hydro-lyase (2-[(ω-methylsulfanyl)alkyl]maleate-forming)

Comments:

The enzyme, characterized from the plant Arabidopsis thaliana, is involved in the L-methionine side-chain elongation pathway, forming substrates for the biosynthesis of aliphatic glucosinolates. By catalysing a dehydration of a 2-[(ω-methylsulfanyl)alkyl]maleate, followed by a hydration at a different position, the enzyme achieves the isomerization of its substrates. The enzyme is a heterodimer comprising a large and a small subunits. The large subunit can also bind to an alternative small subunit, forming EC 4.2.1.33, 3-isopropylmalate dehydratase, which participates in L-leucine biosynthesis.

Links to other databases:

BRENDA, EXPASY, KEGG, MetaCyc

References:

Knill, T., Reichelt, M., Paetz, C., Gershenzon, J. and Binder, S. Arabidopsis thaliana encodes a bacterial-type heterodimeric isopropylmalate isomerase involved in both Leu biosynthesis and the Met chain elongation pathway of glucosinolate formation. Plant Mol. Biol. 71 (2009) 227–239. [DOI] [PMID: 19597944]

[EC 4.2.1.170 created 2016]