1i78: Difference between revisions

[[Image:1i78.jpg|left|200px]]<br /><applet load="1i78" size="350" color="white" frame="true" align="right" spinBox="true"  

OmpT from Escherichia coli belongs to a family of highly homologous outer membrane proteases, known as omptins, which are implicated in the virulence of several pathogenic Gram-negative bacteria. Here we present the crystal structure of OmpT, which shows a 10-stranded antiparallel beta-barrel that protrudes far from the lipid bilayer into the extracellular space. We identified a putative binding site for lipopolysaccharide, a molecule that is essential for OmpT activity. The proteolytic site is located in a groove at the extracellular top of the vase-shaped beta-barrel. Based on the constellation of active site residues, we propose a novel proteolytic mechanism, involving a His-Asp dyad and an Asp-Asp couple that activate a putative nucleophilic water molecule. The active site is fully conserved within the omptin family. Therefore, the structure described here provides a sound basis for the design of drugs against omptin-mediated bacterial pathogenesis. Coordinates are in the Protein Data Bank (accession No. 1I78)

1I78 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli] with <scene name='pdbligand=BOG:'>BOG</scene> and <scene name='pdbligand=MPD:'>MPD</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Omptin Omptin], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.4.23.49 3.4.23.49] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1I78 OCA].  

[[Category: Egmond, M R.]]

[[Category: Kramer, R A.]]

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