1ks9

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spinqualitylabelsall models 1ks9, resolution 1.70Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image

Ketopantoate Reductase from Escherichia coli

Overview

Ketopantoate reductase (KPR, EC 1.1.1.169) catalyzes the NADPH-dependent, reduction of ketopantoate to pantoate on the pantothenate (vitamin B(5)), biosynthetic pathway. The Escherichia coli panE gene encoding KPR was, cloned and expressed at high levels as the native and, selenomethionine-substituted (SeMet) proteins. Both native and SeMet, recombinant proteins were purified by three chromatographic steps, to, yield pure proteins. The wild-type enzyme was found to have a K(M)(NADPH), of 20 microM, a K(M)(ketopantoate) of 60 microM, and a k(cat) of 40 s(-1)., Regular prismatic KPR crystals were prepared using the hanging drop, technique. They belonged to the tetragonal space group P4(2)2(1)2, with, cell parameters: a = b = 103.7 A and c = 55.7 A, accommodating one enzyme, molecule per asymmetric unit. The structure of KPR was determined by the, multiwavelength anomalous dispersion method using the SeMet protein, for, which data were collected to 2.3 A resolution. The native data were, collected to 1.7 A resolution and used to refine the final structure. The, secondary structure comprises 12 alpha-helices, three 3(10)-helices, and, 11 beta-strands. The enzyme is monomeric and has two domains separated by, a cleft. The N-terminal domain has an alphabeta-fold of the Rossmann type., The C-terminal domain (residues 170-291) is composed of eight, alpha-helices. KPR is shown to be a member of the 6-phosphogluconate, dehydrogenase C-terminal domain-like superfamily. A model for the ternary, enzyme-NADPH-ketopantoate ternary complex provides a rationale for kinetic, data reported for specific site-directed mutants.

About this Structure

1KS9 is a Single protein structure of sequence from Escherichia coli. Active as 2-dehydropantoate 2-reductase, with EC number 1.1.1.169 Full crystallographic information is available from OCA.

Reference

Crystal structure of Escherichia coli ketopantoate reductase at 1.7 A resolution and insight into the enzyme mechanism., Matak-Vinkovic D, Vinkovic M, Saldanha SA, Ashurst JL, von Delft F, Inoue T, Miguel RN, Smith AG, Blundell TL, Abell C, Biochemistry. 2001 Dec 4;40(48):14493-500. PMID:11724562

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