1d9e

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Revision as of 10:58, 20 November 2007

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spinqualitylabelsall models 1d9e, resolution 2.4Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image

STRUCTURE OF E. COLI KDO8P SYNTHASE

Overview

3-deoxy-D-manno-octulosonate 8-phosphate (KDO8P) synthase catalyzes the, condensation of phosphoenolpyruvate (PEP) with arabinose 5-phosphate (A5P), to form KDO8P and inorganic phosphate. KDO8P is the phosphorylated, precursor of 3-deoxy-D-manno-octulosonate, an essential sugar of the, lipopolysaccharide of Gram-negative bacteria. The crystal structure of the, Escherichia coli KDO8P synthase has been determined by multiple wavelength, anomalous diffraction and the model has been refined to 2.4 A (R-factor, 19.9%; R-free, 23.9%). KDO8P synthase is a homotetramer in which each, monomer has the fold of a (beta/alpha)(8) barrel. On the basis of the, features of the active site, PEP and A5P are predicted to bind with their, phosphate moieties 13 A apart such that KDO8P synthesis would proceed via, a linear intermediate. A reaction similar to KDO8P synthesis, the, condensation of phosphoenolpyruvate, and erythrose 4-phosphate to form, 3-deoxy-D-arabino-heptulosonate 7-phosphate (DAH7P), is catalyzed by DAH7P, synthase. In the active site of DAH7P synthase the two substrates PEP and, erythrose 4-phosphate appear to bind in a configuration similar to that, proposed for PEP and A5P in the active site of KDO8P synthase. This, observation suggests that KDO8P synthase and DAH7P synthase evolved from a, common ancestor and that they adopt the same catalytic strategy.

About this Structure

1D9E is a Single protein structure of sequence from Escherichia coli with SO4 as ligand. Active as 3-deoxy-8-phosphooctulonate synthase, with EC number 2.5.1.55 Full crystallographic information is available from OCA.

Reference

Structure and mechanism of 3-deoxy-D-manno-octulosonate 8-phosphate synthase., Radaev S, Dastidar P, Patel M, Woodard RW, Gatti DL, J Biol Chem. 2000 Mar 31;275(13):9476-84. PMID:10734095

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