1yiy

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Revision as of 02:03, 25 November 2007

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spinqualitylabelsall models 1yiy, resolution 1.9Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image

Aedes aegypti kynurenine aminotransferase

Overview

Aedes aegypti kynurenine aminotransferase (AeKAT) catalyzes the, irreversible transamination of kynurenine to kynurenic acid, the natural, antagonist of NMDA and 7-nicotinic acetycholine receptors. Here, we report, the crystal structure of AeKAT in its PMP and PLP forms at 1.90 and 1.55, A, respectively. The structure was solved by a combination of, single-wavelength anomalous dispersion and molecular replacement, approaches. The initial search model in the molecular replacement method, was built with the result of single-wavelength anomalous dispersion data, from the Br-AeKAT crystal in combination with homology modeling. The, solved structure shows that the enzyme is a homodimer, and that the two, subunits are stabilized by a number of hydrogen bonds, salts bridges, and, hydrophobic interactions. Each subunit is divided into an N-terminal arm, and small and large domains. Based on its folding, the enzyme belongs to, the prototypical fold type, aminotransferase subgroup I. The, three-dimensional structure shows a strictly conserved 'PLP-phosphate, binding cup' featuring PLP-dependent enzymes. The interaction between, Cys284 (A) and Cys284 (B) is unique in AeKAT, which might explain the, cysteine effect of AeKAT activity. Further mutation experiments of this, residue are needed to eventually understand the mechanism of the enzyme, modulation by cysteine.

About this Structure

1YIY is a Single protein structure of sequence from Aedes aegypti with BR and PMP as ligands. Full crystallographic information is available from OCA.

Reference

Crystal structures of Aedes aegypti kynurenine aminotransferase., Han Q, Gao YG, Robinson H, Ding H, Wilson S, Li J, FEBS J. 2005 May;272(9):2198-206. PMID:15853804

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