1ex9
From Proteopedia
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CRYSTAL STRUCTURE OF THE PSEUDOMONAS AERUGINOSA LIPASE COMPLEXED WITH RC-(RP,SP)-1,2-DIOCTYLCARBAMOYL-GLYCERO-3-O-OCTYLPHOSPHONATE
Overview
The x-ray structure of the lipase from Pseudomonas aeruginosa PAO1 has, been determined at 2.54 A resolution. It is the first structure of a, member of homology family I.1 of bacterial lipases. The structure shows a, variant of the alpha/beta hydrolase fold, with Ser(82), Asp(229), and, His(251) as the catalytic triad residues. Compared with the "canonical", alpha/beta hydrolase fold, the first two beta-strands and one alpha-helix, (alphaE) are not present. The absence of helix alphaE allows the formation, of a stabilizing intramolecular disulfide bridge. The loop containing, His(251) is stabilized by an octahedrally coordinated calcium ion. On top, of the active site a lid subdomain is in an open conformation, making the, catalytic cleft accessible from the solvent region. A triacylglycerol, analogue is covalently bound to Ser(82) in the active site, demonstrating, the position of the oxyanion hole and of the three pockets that, accommodate the sn-1, sn-2, and sn-3 fatty acid chains. The inhibited, enzyme can be thought to mimic the structure of the tetrahedral, intermediate that occurs during the acylation step of the reaction., Analysis of the binding mode of the inhibitor suggests that the size of, the acyl pocket and the size and interactions of the sn-2 binding pocket, are the predominant determinants of the regio- and enantio-preference of, the enzyme.
About this Structure
1EX9 is a Single protein structure of sequence from Pseudomonas aeruginosa with CA and OCP as ligands. Active as Triacylglycerol lipase, with EC number 3.1.1.3 Full crystallographic information is available from OCA.
Reference
Crystal structure of pseudomonas aeruginosa lipase in the open conformation. The prototype for family I.1 of bacterial lipases., Nardini M, Lang DA, Liebeton K, Jaeger KE, Dijkstra BW, J Biol Chem. 2000 Oct 6;275(40):31219-25. PMID:10893416
Page seeded by OCA on Tue Nov 20 14:23:46 2007
