Characterization of alpha-ketoglutarate-dependent taurine dioxygenase from Escherichia coli.

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Eichhorn E, van der Ploeg JR, Kertesz MA, Leisinger T

Characterization of alpha-ketoglutarate-dependent taurine dioxygenase from Escherichia coli.

J Biol Chem. 1997 Sep 12;272(37):23031-6.

PubMed ID

9287300 [ View in PubMed

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Abstract

The Escherichia coli tauD gene is required for the utilization of taurine (2-aminoethanesulfonic acid) as a sulfur source and is expressed only under conditions of sulfate starvation. The sequence relatedness of the TauD protein to the alpha-ketoglutarate-dependent 2,4-dichlorophenoxyacetate dioxygenase of Alcaligenes eutrophus suggested that TauD is an alpha-ketoglutarate-dependent dioxygenase catalyzing the oxygenolytic release of sulfite from taurine (van der Ploeg, J. R., Weiss, M. A., Saller, E., Nashimoto, H., Saito, N., Kertesz, M. A., and Leisinger, T. (1996) J. Bacteriol. 178, 5438-5446). TauD was overexpressed in E. coli to approximately 70% of the total soluble protein and purified to apparent homogeneity by a simple two-step procedure. The apparent Mr of 81,000 of the native protein and the subunit Mr of 37,400 were consistent with a homodimeric structure. The pure enzyme converted taurine to sulfite and aminoacetaldehyde, which was identified by high pressure liquid chromatography after enzymatic conversion to ethanolamine. The reaction also consumed equimolar amounts of oxygen and alpha-ketoglutarate; ferrous iron was absolutely required for activity; and ascorbate stimulated the reaction. The properties and amino acid sequence of this enzyme thus define it as a new member of the alpha-ketoglutarate-dependent dioxygenase family. The pure enzyme showed maximal activity at pH 6.9 and retained activity on storage at -20 degrees C for several weeks. Taurine (Km = 55 microM) was the preferred substrate, but pentanesulfonic acid, 3-(N-morpholino)propanesulfonic acid, and 1,3-dioxo-2-isoindolineethanesulfonic acid were also desulfonated at significant rates. Among the cosubstrates tested, only alpha-ketoglutarate (Km = 11 microM) supported significant dioxygenase activity.

DrugBank Data that Cites this Article

Drug Targets

Drug	Target	Kind	Organism	Pharmacological Action	Actions
Taurine	Alpha-ketoglutarate-dependent taurine dioxygenase	Protein	Escherichia coli (strain K12)	Unknown	Not Available	Details

Polypeptides

Name	UniProt ID
Alpha-ketoglutarate-dependent taurine dioxygenase	P37610	Details