Fig. 2: Structural models of dihydroxy acid dehydratase (DHAD) and 6-phosphogluconate dehydratase (EDD). | Nature Communications

Fig. 2: Structural models of dihydroxy acid dehydratase (DHAD) and 6-phosphogluconate dehydratase (EDD).

From: Plastid ancestors lacked a complete Entner-Doudoroff pathway, limiting plants to glycolysis and the pentose phosphate pathway

Fig. 2

a Dehydration of 2,3-dihydroxyisovalerate by DHAD in the branched chain amino acid pathway. b Dehydration of 6-phosphogluconate by EDD in the ED pathway. OP signifies a phosphate group. c The crystal structure of the Arabidopsis thaliana DHAD (PDB ID: 5ZE4) depicting a crystallographic dimer in green and yellow and (d) our model of the Escherichia coli EDD (ACA77431) dimer in cyan and purple with domains 1 (D1) and 2 (D2) shown in orange and pink, respectively. e Predicted substrate binding of 2,3-dihydroxyisovalerate in the active site of DHAD. f The analogous binding of 6-phosphogluconate in the EDD active site. The reciprocal docking experiments did not support binding when the substrates were switched. The magnesium ion and 2Fe-2S clusters of each protein are shown in blue and red, respectively. Dotted black lines in (e) and (f) denote predicted polar contacts between substrate and surrounding residues and ions.

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