Crystal structure of the outer membrane protease OmpT from Escherichia coli suggests a novel catalytic site

Autor: Maarten R. Egmond, R.Arjen Kramer, Niek Dekker, Jan Kroon, Piet Gros, Lucy Vandeputte-Rutten
Rok vydání: 2001
Předmět:
Zdroj: EMBO Journal, 20(18), 5033. European Molecular Biology Organization
ISSN: 1460-2075
0261-4189
Popis: 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)
Databáze: OpenAIRE