MetaCyc Enzyme: 4-oxalomesaconate hydratase

Gene: ligJ Accession Number: G-2547 (MetaCyc)

Synonyms: DMA hydratase, 4-carboxy-2-hydroxymuconate hydratase

Species: Sphingomonas sp. SYK6

Subunit composition of 4-oxalomesaconate hydratase = [LigJ]2
         4-oxalomesaconate hydratase monomer = LigJ

The ligJ gene of Sphingomonas sp. SYK6, which encodes 4-oxalomesaconate hydratase, was found in the gene cluster carrying the genes for several enzymes involved in protocatechuate degradation [Hara00]. The gene was cloned and expressed in Escherichia coli, and the recombinant protein was purified to near homogeneity and characterized. The enzyme was found to be a homodimer of 69.5 kDa by gel filtration chromatography. Activity was inhibited by the addition of thiol reagents, suggesting that a cysteine residue is part of the catalytic site.

A ligJ gene disruption in Sphingomonas sp. SYK6 caused accumulation of common metabolites from both vanillate and syringate.

Gene Citations: [Noda90, Masai99]

Molecular Weight of Polypeptide: 38.052 kD (from nucleotide sequence)

Molecular Weight of Multimer: 69.5 kD (experimental) [Hara00]

pI: 4.9 [Hara00]

Unification Links: Protein Model Portal:Q9KWL6 , SMR:Q9KWL6 , UniProt:Q9KWL6

Relationship Links: Entrez-Nucleotide:PART-OF:AB035121 , InterPro:IN-FAMILY:IPR006992 , Pfam:IN-FAMILY:PF04909

Gene-Reaction Schematic: ?

Gene-Reaction Schematic

Revised 25-Sep-2009 by Caspi R , SRI International

Enzymatic reaction of: 4-oxalomesaconate hydratase

EC Number:

2-hydroxy-4-oxobutane-1,2,4-tricarboxylate <=> (1E,3E)-4-hydroxybuta-1,3-diene-1,2,4-tricarboxylate + H2O

The reaction direction shown, that is, A + B ↔ C + D versus C + D ↔ A + B, is in accordance with the Enzyme Commission system.

This reaction is reversible.

In Pathways: superpathway of vanillin and vanillate degradation , syringate degradation , protocatechuate degradation I (meta-cleavage pathway) , methylgallate degradation , gallate degradation I

Activators (Unknown Mechanism): L-cysteine [Hara00]

Inhibitors (Unknown Mechanism): Hg2+ [Hara00]

Kinetic Parameters:

Km (μM)

T(opt): 30 °C [Hara00]


Hara00: Hara H, Masai E, Katayama Y, Fukuda M (2000). "The 4-oxalomesaconate hydratase gene, involved in the protocatechuate 4,5-cleavage pathway, is essential to vanillate and syringate degradation in Sphingomonas paucimobilis SYK-6." J Bacteriol 182(24);6950-7. PMID: 11092855

Masai99: Masai E, Shinohara S, Hara H, Nishikawa S, Katayama Y, Fukuda M (1999). "Genetic and biochemical characterization of a 2-pyrone-4, 6-dicarboxylic acid hydrolase involved in the protocatechuate 4, 5-cleavage pathway of Sphingomonas paucimobilis SYK-6." J Bacteriol 181(1);55-62. PMID: 9864312

Noda90: Noda Y, Nishikawa S, Shiozuka K, Kadokura H, Nakajima H, Yoda K, Katayama Y, Morohoshi N, Haraguchi T, Yamasaki M (1990). "Molecular cloning of the protocatechuate 4,5-dioxygenase genes of Pseudomonas paucimobilis." J Bacteriol 172(5);2704-9. PMID: 2185230

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Please cite the following article in publications resulting from the use of MetaCyc: Caspi et al, Nucleic Acids Research 42:D459-D471 2014
Page generated by SRI International Pathway Tools version 19.0 on Tue Jul 28, 2015, biocyc13.