InterPro domain: IPR004404

Two dehydratases, dihydroxy-acid dehydratase (gene ilvD or ILV3) and 6-phosphogluconatedehydratase (gene edd) have been shown to be evolutionary related [ 1 ]. Dihydroxy-aciddehydratase catalyzes the fourth step in the biosynthesis of isoleucine and valine, the dehydratation of2,3-dihydroxy-isovaleic acid into alpha-ketoisovaleric acid. 6-Phosphogluconate dehydratase catalyzes thefirst step in the Entner-Doudoroff pathway, the dehydratation of 6-phospho-D-gluconate into 6-phospho-2-dehydro-3-deoxy-D-gluconate. Another protein containing this signature is the Escherichia coli hypothetical proteinyjhG. The N-terminal part of the proteins contains a cysteine that could be involved in the binding of a2Fe-2S iron-sulphur cluster [ 2 ].

This family represents dihydroxy-acid dehydratase (DAD). It contains a catalytically essential [4Fe-4S] cluster and catalyses the fourth step in valine and isoleucine biosynthesis.

1. Molecular characterization of the Entner-Doudoroff pathway in Escherichia coli: sequence analysis and localization of promoters for the edd-eda operon. J. Bacteriol. 174, 4638-46
2. Cloning of the dihydroxyacid dehydratase-encoding gene (ILV3) from Saccharomyces cerevisiae. Gene 137, 179-85