IUBMB Enzyme Nomenclature


Accepted name: muconate cycloisomerase

Reaction: 2,5-dihydro-5-oxofuran-2-acetate = cis,cis-hexadienedioate

For diagram click here (another example).

Glossary: muconolactone = (2,5-dihydro-5-oxofuran-2-yl)acetate
cis,cis-hexadienedioate = (2Z,4Z)-hexa-2,4-dienedioate = cis,cis-muconate

Other name(s): muconate cycloisomerase I; cis,cis-muconate-lactonizing enzyme; cis,cis-muconate cycloisomerase; muconate lactonizing enzyme; 4-carboxymethyl-4-hydroxyisocrotonolactone lyase (decyclizing); CatB; MCI; 2,5-dihydro-5-oxofuran-2-acetate lyase (decyclizing)

Systematic name: 2,5-dihydro-5-oxofuran-2-acetate lyase (ring-opening)

Comments: Requires Mn2+. Also acts (in the reverse reaction) on 3-methyl-cis,cis-hexadienedioate and, very slowly, on cis,trans-hexadienedioate. Not identical with EC (chloromuconate cycloisomerase) or EC (dichloromuconate cycloisomerase).

Links to other databases: BRENDA, EAWAG-BBD, EXPASY, GTD, KEGG, Metacyc, PDB, CAS registry number: 9023-72-7


1. Ornston, L.N. The conversion of catechol and protocatechuate to β-ketoadipate by Pseudomonas putida. 3. Enzymes of the catechol pathway. J. Biol. Chem. 241 (1966) 3795-3799. [PMID: 5330966]

2. Ornston, L.N. Conversion of catechol and protocatechuate to β-ketoadipate (Pseudomonas putida). Methods Enzymol. 17A (1970) 529-549.

3. Sistrom, W.R. and Stanier, R.Y. The mechanism of formation of β-ketoadipic acid by bacteria. J. Biol. Chem. 210 (1954) 821-836.

[EC created 1961]

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