Accepted name: chloromuconate cycloisomerase
Reaction: (2R)-2-chloro-2,5-dihydro-5-oxofuran-2-acetate = 3-chloro-cis,cis-muconate
Glossary: (2R)-2-chloro-2,5-dihydro-5-oxofuran-2-acetate = (+)-4-chloromuconolactone
3-chloro-cis,cis-muconate = (2E,4Z)-3-chlorohexa-2,4-dienedioate
Other name(s): muconate cycloisomerase II; 2-chloro-2,5-dihydro-5-oxofuran-2-acetate lyase (decyclizing); 2-chloro-2,5-dihydro-5-oxofuran-2-acetate lyase (ring-opening)
Systematic name: (2R)-2-chloro-2,5-dihydro-5-oxofuran-2-acetate lyase (ring-opening)
Comments: Requires Mn2+. The product of cycloisomerization of 3-chloro-cis,cis-muconate spontaneously eliminates chloride to produce cis-4-carboxymethylenebut-2-en-4-olide. Also acts on 2-chloro-cis,cis-muconate. Not identical with EC (muconate cycloisomerase) or EC (dichloromuconate cycloisomerase).
1.  Schmidt, E. and Knackmuss, H.-J. Chemical structure and biodegradability of halogenated aromatic compounds. Conversion of chlorinated muconic acids into maleoylacetic acid. Biochem. J. 192 (1980) 339–347. [PMID: 7305906]
2.  Kaulmann, U., Kaschabek, S.R. and Schlomann, M. Mechanism of chloride elimination from 3-chloro- and 2,4-dichloro-cis,cis-muconate: new insight obtained from analysis of muconate cycloisomerase variant CatB-K169A. J. Bacteriol. 183 (2001) 4551–4561. [PMID: 11443090]
3.  Kajander, T., Lehtio, L., Schlomann, M. and Goldman, A. The structure of Pseudomonas P51 Cl-muconate lactonizing enzyme: co-evolution of structure and dynamics with the dehalogenation function. Protein Sci. 12 (2003) 1855–1864. [PMID: 12930985]
[EC created 1983]