Family

D-Glucarate dehydratase-like (IPR034598)

Short name: GlucD-like

Family relationships

Description

D-Glucarate dehydratase (GlucD) catalyzes the dehydration of both D-glucarate and L-idarate to form 5-keto-4-deoxy-D-glucarate (5-KDG) , the initial reaction of the catabolic pathway for (D)-glucarate. GlucD belongs to the enolase superfamily of enzymes, characterized by the presence of an enolate anion intermediate which is generated by abstraction of the alpha-proton of the carboxylate substrate by an active site residue and that is stabilized by coordination to the essential Mg2+ ion [PMID: 9772162, PMID: 1513584, PMID: 15581566, PMID: 8987982].

The glucarate dehydratase family has a similar constellation of active site residues to the mandelate racemase family, including a conserved histidine, presumably acting as an active site base (H339 in E. coli glucarate dehydratase) and a conserved aspartic acid that controls the pKa of this histidine (D313 in E. coli glucarate dehydratase). However, in the glucarate dehydratase family, the third metal ligand is an Asn rather than an Asp/Glu as in the mandelate racemase family. Furthermore, structural alignments show that the third metal binding ligand of the glucarate dehydratase family is offset by one position from that of the mandelate racemase family. Currently, the only characterized enzyme is glucarate dehydratase, though other enzymes in the family have also been shown to catalyze the glucarate dehydratase reaction, but only at very low levels. It is unclear what the biologically relevant reaction for these sequences is [PMID: 11513584].

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.
CDD
  • cd03323 (D-glucarate_dehydratase)
SFLD