IUBMB Enzyme Nomenclature


Accepted name: L-tyrosine isonitrile synthase

Reaction: L-tyrosine + D-ribulose 5-phosphate = (2S)-3-(4-hydroxyphenyl)-2-isocyanopropanoate + hydroxyacetone + formaldehyde + phosphate + H2O

For diagram of reaction click here

Glossary: (2S)-3-(4-hydroxyphenyl)-2-isocyanopropanoate = L-tyrosine isonitrile
paerucumarin = 6,7-dihydroxy-3-isocyanochromen-2-one
rhabduscin = N-[(2S,3S,4R,5S,6R)-4,5-dihydroxy-6-{4-[(E)-2-isocyanoethenyl]phenoxy}-2-methyloxan-3-yl]acetamide

Other name(s): pvcA (gene name)

Systematic name: L-tyrosine:D-ribulose-5-phosphate lyase (isonitrile-forming)

Comments: The enzymes from the bacteria Pseudomonas aeruginosa and Xenorhabdus nematophila are involved in the biosynthesis of paerucumarin and rhabduscin, respectively. According to the proposed mechanism, the enzyme forms an imine intermediate composed of linked L-tyrosine 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, L-tryptophan isonitrile synthase.

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number:


1. Clarke-Pearson, M.F. and Brady, S.F. Paerucumarin, a new metabolite produced by the pvc gene cluster from Pseudomonas aeruginosa. J. Bacteriol. 190 (2008) 6927-6930. [PMID: 18689486]

2. Drake, E.J. and Gulick, A.M. Three-dimensional structures of Pseudomonas aeruginosa PvcA and PvcB, two proteins involved in the synthesis of 2-isocyano-6,7-dihydroxycoumarin. J. Mol. Biol. 384 (2008) 193-205. [PMID: 18824174]

3. Chang, W.C., Sanyal, D., Huang, J.L., Ittiamornkul, K., Zhu, Q. and Liu, X. In vitro stepwise reconstitution of amino acid derived vinyl isocyanide biosynthesis: detection of an elusive intermediate. Org. Lett. 19 (2017) 1208-1211. [PMID: 28212039]

[EC created 2018]

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