InterPro: IPR004404 Dihydroxy-acid dehydratase

Two dehydratases, dihydroxy-acid dehydratase (gene ilvD or ILV3) and 6-phosphogluconate dehydratase (gene edd) have been shown to be evolutionary related [1]. Dihydroxy-acid dehydratase catalyzes the fourth step in the biosynthesis of isoleucine and valine, the dehydratation of 2,3-dihydroxy-isovaleic acid into alpha-ketoisovaleric acid. 6-Phosphogluconate dehydratase catalyzes the first 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 protein yjhG. The N-terminal part of the proteins contains a cysteine that could be involved in the binding of a 2Fe-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.