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EC 4.1.99.25 Details

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EC number

4.1.99.25

Accepted name

L-tryptophan isonitrile synthase

Reaction

L-tryptophan + D-ribulose 5-phosphate = (2S)-3-(1H-indol-3-yl)-2-isocyanopropanoate + hydroxyacetone + formaldehyde + phosphate + H₂O

Other name(s)

isnA (gene name), ambI1 (gene name), well1 (gene name)

Systematic name

L-tryptophan:D-ribulose-5-phosphate lyase (isonitrile-forming)

Comment

The enzymes from cyanobacteria that belong to the Nostocales order participate in the biosynthesis of hapalindole-type alkaloids. According to the proposed mechanism, the enzyme forms an imine intermediate composed of linked L-tryptophan and D-ribulose 5-phosphate, followed by loss of the phosphate group and formation of a β-keto imine and keto-enol tautomerization. This is followed by a C-C bond cleavage, the release of hydroxyacetone, and a retro aldol type reaction that releases formaldehyde and forms the final product [3]. cf. EC 4.1.99.24, L-tyrosine isonitrile synthase.

History

created 2018

EC Tree

1 Oxidoreductases

1.1 Acting on the CH-OH group of donors

1.1.1 With NAD⁺ or NADP⁺ as acceptor

1.1.2 With a cytochrome as acceptor

1.1.3 With oxygen as acceptor

1.1.4 With a disulfide as acceptor

1.1.5 With a quinone or similar compound as acceptor

1.1.7 With an iron-sulfur protein as acceptor

1.1.9 With a copper protein as acceptor

1.1.98 With other, known, physiological acceptors

1.1.98.1 alcohol dehydrogenase (azurin)

1.1.98.2 glucose-6-phosphate dehydrogenase (coenzyme-F₄₂₀)

1.1.98.3 decaprenylphospho-β-D-ribofuranose 2-dehydrogenase

1.1.98.4 F₄₂₀H₂:quinone oxidoreductase

1.1.98.5 secondary-alcohol dehydrogenase (coenzyme-F₄₂₀)

1.1.98.6 ribonucleoside-triphosphate reductase (formate)

1.1.98.7 serine-type anaerobic sulfatase-maturating enzyme

1.1.99 With unknown physiological acceptors

1.2 Acting on the aldehyde or oxo group of donors

1.3 Acting on the CH-CH group of donors

1.4 Acting on the CH-NH₂ group of donors

1.5 Acting on the CH-NH group of donors

1.6 Acting on NADH or NADPH

1.7 Acting on other nitrogenous compounds as donors

1.8 Acting on a sulfur group of donors

1.9 Acting on a heme group of donors

1.10 Acting on diphenols and related substances as donors

1.10.1 With NAD⁺ or NADP⁺ as acceptor

1.10.2 With a cytochrome as acceptor

1.10.3 With oxygen as acceptor

1.10.5 With a quinone or related compound as acceptor

1.10.9 With a copper protein as acceptor

1.10.99 With unknown physiological acceptors

1.11 Acting on a peroxide as acceptor

1.12 Acting on hydrogen as donor

1.13 Acting on single donors with incorporation of molecular oxygen (oxygenases)

1.14 Acting on paired donors, with incorporation or reduction of molecular oxygen

1.15 Acting on superoxide as acceptor

1.16 Oxidizing metal ions

1.17 Acting on CH or CH₂ groups

1.18 Acting on iron-sulfur proteins as donors

1.19 Acting on reduced flavodoxin as donor

1.20 Acting on phosphorus or arsenic in donors

1.21 Catalysing the reaction X-H + Y-H = X-Y

1.21.1 With NAD⁺ or NADP⁺ as acceptor

1.21.3 With oxygen as acceptor

1.21.4 With a disulfide as acceptor

1.21.98 With other, known, physiological acceptors

1.21.99 With unknown physiological acceptors

1.22 Acting on halogen in donors

1.23 Reducing C-O-C group as acceptor

1.97 Other oxidoreductases

1.98 Enzymes using H₂ as reductant (deleted subclass)

1.99 Other enzymes using O₂ as oxidant (deleted subclass)

4.1 Carbon-carbon lyases

4.1.1 Carboxy-lyases

4.1.2 Aldehyde-lyases

4.1.3 Oxo-acid-lyases

4.1.99 Other carbon-carbon lyases

4.1.99.1 tryptophanase

4.1.99.2 tyrosine phenol-lyase

4.1.99.3 deoxyribodipyrimidine photo-lyase

4.1.99.4 created 1981, deleted 2002

4.1.99.5 aldehyde oxygenase (deformylating)

4.1.99.6 created 1989, deleted 2000

4.1.99.7 created 1992 as EC 2.5.1.40, transferred 1999 to EC 4.1.99.7, deleted 2000

4.1.99.8 created 2000, deleted 2000

4.1.99.9 created 2000, deleted 2000

4.1.99.10 created 2000, deleted 2000

4.1.99.11 benzylsuccinate synthase

4.1.99.12 3,4-dihydroxy-2-butanone-4-phosphate synthase

4.1.99.13 (6-4)DNA photolyase

4.1.99.14 spore photoproduct lyase

4.1.99.15 S-specific spore photoproduct lyase

4.1.99.16 geosmin synthase

4.1.99.17 phosphomethylpyrimidine synthase

4.1.99.18 cyclic pyranopterin phosphate synthase

4.1.99.19 2-iminoacetate synthase

4.1.99.20 3-amino-4-hydroxybenzoate synthase

4.1.99.21 (5-formylfuran-3-yl)methyl phosphate synthase

4.1.99.22 GTP 3′,8-cyclase

4.1.99.23 5-hydroxybenzimidazole synthase

4.1.99.24 L-tyrosine isonitrile synthase

4.1.99.25 L-tryptophan isonitrile synthase

4.1.99.26 3-amino-5-[(4-hydroxyphenyl)methyl]-4,4-dimethylpyrrolidin-2-one synthase

4.2 Carbon-oxygen lyases

4.3 Carbon-nitrogen lyases

4.4 Carbon-sulfur lyases

4.5 Carbon-halide lyases

4.6 Phosphorus-oxygen lyases

4.7 carbon-phosphorus lyases

4.8 Nitrogen-oxygen lyases

4.98 ATP-independent chelatases

4.99 Other lyases

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Release 2023.1 (January 2023)