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1.13.11.72

evolution

2-hydroxyethylphosphonate dioxygenase (HEPD) and methylphosphonate synthase (MPnS) are non-heme iron oxygenases that both catalyze the carbon-carbon bond cleavage of 2-hydroxyethylphosphonate but generate different products. Both HEPD and MPnS generate a methylphosphonate radical. Substrate labeling experiments lead to a mechanistic hypothesis in which the fate of a common intermediate determines product identity, overview. Primary sequences and homology modeling suggest that the architectures of the active sites of HEPD and MPnS are similar

1.13.11.72

evolution

2-hydroxyethylphosphonate dioxygenase (HEPD) and methylphosphonate synthase (MPnS) are non-heme iron oxygenases that both catalyze the carbon-carbon bond cleavage of 2-hydroxyethylphosphonate but generate different products. Both HEPD and MPnS generate a methylphosphonate radical. Substrate labeling experiments lead to a mechanistic hypothesis in which the fate of a common intermediate determines product identity, overview. Primary sequences and homology modeling suggest that the architectures of the active sites of HEPD and MPnS are similar; one group of mononuclear non-heme iron-dependent enzymes includes 2-hydroxyethylphosphonate dioxygenase (HEPD) and methylphosphonate synthase (MPnS, EC 1.13.11.73) that both carry out the oxidative cleavage of the carbon-carbon bond of 2-hydroxyethylphosphonate but generate different products. Common properties include the initial substrate oxidation by a ferric-superoxo-intermediate and a second oxidation by a ferryl species. Sequence homology between HEPD and MPnS combined with identical requirements for catalysis suggests a consensus mechanism in which product identity is determined by branching at an intermediate in the catalytic cycle

1.13.11.72

evolution

one group of mononuclear non-heme iron-dependent enzymes includes 2-hydroxyethylphosphonate dioxygenase (HEPD) and methylphosphonate synthase (MPnS, EC 1.13.11.73) that both carry out the oxidative cleavage of the carbon-carbon bond of 2-hydroxyethylphosphonate but generate different products. Common properties include the initial substrate oxidation by a ferric-superoxo-intermediate and a second oxidation by a ferryl species. Sequence homology between HEPD and MPnS combined with identical requirements for catalysis suggests a consensus mechanism in which product identity is determined by branching at an intermediate in the catalytic cycle

1.13.11.72

more

the active site metal is coordinated by 2-His-1-Glu on one face of a pseudooctrahedron

1.13.11.72

physiological function

2-hydroxyethylphosphonate dioxygenase (HEPD) cleaves the C1-C2 bond of its substrate to afford hydroxymethylphosphonate on the biosynthetic pathway to the commercial herbicide phosphinothricin