1hj6

From Proteopedia

Revision as of 13:31, 30 October 2007

ISOCITRATE DEHYDROGENASE S113E MUTANT COMPLEXED WITH ISOPROPYLMALATE, NADP+ AND MAGNESIUM (FLASH-COOLED)

Overview

Isocitrate dehydrogenase (IDH) catalyzes the oxidative decarboxylation of, isocitrate and has negligible activity toward other (R)-malate-type, substrates. The S113E mutant of IDH significantly improves its ability to, utilize isopropylmalate as a substrate and switches the substrate, specificity (k(cat)/K(M)) from isocitrate to isopropylmalate. To, understand the structural basis for this switch in substrate specificity, we have determined the crystal structure of IDH S113E in a complex with, isopropylmalate, NADP, and Mg(2+) to 2.0 A resolution. On the basis of a, comparison with previously determined structures, we identify distinct, changes caused by the amino acid substitution and by the binding of, substrates. The S113E complex exhibits alterations in global and active, site ... [(full description)]

About this Structure

1HJ6 is a [Single protein] structure of sequence from [Escherichia coli] with MG, IPM, NAP and GOL as [ligands]. Active as [Isocitrate dehydrogenase (NADP(+))], with EC number [1.1.1.42]. Structure known Active Sites: IPM, MG and NAP. Full crystallographic information is available from [OCA].

Reference

Structural basis for a change in substrate specificity: crystal structure of S113E isocitrate dehydrogenase in a complex with isopropylmalate, Mg2+, and NADP., Doyle SA, Beernink PT, Koshland DE Jr, Biochemistry. 2001 Apr 10;40(14):4234-41. PMID:11284679

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