Loading...
4-sulfomuconolactone hydrolases from Hydrogenophaga intermedia S1 and Agrobacterium radiobacter S2.
Halak, Sad Basta, Tamara Bürger, Sibylle Contzen, Matthias Wray, Victor Pieper, Dietmar Helmut Stolz, Andreas
Halak, Sad
Basta, Tamara
Bürger, Sibylle
Contzen, Matthias
Wray, Victor
Pieper, Dietmar Helmut
Stolz, Andreas
Citations
Altmetric:
Advisors
Editors
Other Contributors
Issue Date
2007-10
Submitted date
Files
Loading...
allowed publisher's PDF
Adobe PDF, 329.19 KB
Other Titles
Abstract
The 4-carboxymethylen-4-sulfo-but-2-en-olide (4-sulfomuconolactone) hydrolases from Hydrogenophaga intermedia strain S1 and Agrobacterium radiobacter strain S2 are part of a modified protocatechuate pathway responsible for the degradation of 4-sulfocatechol. In both strains, the hydrolase-encoding genes occur downstream of those encoding the enzymes that catalyze the lactonization of 3-sulfomuconate. The deduced amino acid sequences of the 4-sulfomuconolactone hydrolases demonstrated the highest degree of sequence identity to 2-pyrone-4,6-dicarboxylate hydrolases, which take part in the meta cleavage pathway of protocatechuate. The 4-sulfomuconolactone hydrolases did not convert 2-pyrone-4,6-dicarboxylate, and the 2-pyrone-4,6-dicarboxylate hydrolase from Sphingomonas paucimobilis SYK-6 did not convert 4-sulfomuconolactone. Nevertheless, the presence of highly conserved histidine residues in the 4-sulfomuconolactone and the 2-pyrone-4,6-dicarboxylate hydrolases and some further sequence similarities suggested that both enzymes belong to the metallo-dependent hydrolases (the "amidohydrolase superfamily"). The 4-sulfomuconolactone hydrolases were heterologously expressed as His-tagged enzyme variants. Gel filtration experiments suggested that the enzymes are present as monomers in solution, with molecular weights of approximately 33,000 to 35,000. 4-Sulfomuconolactone was converted by sulfomuconolactone hydrolases to stoichiometric amounts of maleylacetate and sulfite. The 4-sulfomuconolactone hydrolases from both strains showed pH optima at pH 7 to 7.5 and rather similar catalytic constant (k(cat)/K(M))values. The suggested 4-sulfocatechol pathway from 4-sulfocatechol to maleylacetate was confirmed by in situ nuclear magnetic resonance analysis using the recombinantly expressed enzymes.
Citation
4-sulfomuconolactone hydrolases from Hydrogenophaga intermedia S1 and Agrobacterium radiobacter S2. 2007, 189 (19):6998-7006 J. Bacteriol.
Publisher
Journal
PubMed ID
PubMed Central ID
Embedded video
Type
Article
Language
en
Description
Series/Report no.
ISSN
0021-9193