1gzs

From Proteopedia

Revision as of 13:39, 18 December 2007

CRYSTAL STRUCTURE OF THE COMPLEX BETWEEN THE GEF DOMAIN OF THE SALMONELLA TYPHIMURIUM SOPE TOXIN AND HUMAN CDC42

Overview

The bacterial enteropathogen Salmonella typhimurium employs a type III, secretion system to inject bacterial toxins into the host cell cytosol., These toxins transiently activate Rho family GTP-binding protein-dependent, signaling cascades to induce cytoskeletal rearrangements. One of these, translocated Salmonella toxins, SopE, can activate Cdc42 in a Dbl-like, fashion despite its lack of sequence similarity to Dbl-like proteins, the, Rho-specific eukaryotic guanine nucleotide exchange factors. To elucidate, the mechanism of SopE-mediated guanine nucleotide exchange, we have, analyzed the structure of the complex between a catalytic fragment of SopE, and Cdc42. SopE binds to and locks the switch I and switch II regions of, Cdc42 in a conformation that promotes guanine nucleotide release. This, conformation is strikingly similar to that of Rac1 in complex with the, eukaryotic Dbl-like exchange factor Tiam1. However, the catalytic domain, of SopE has an entirely different architecture from that of Tiam1 and, interacts with the switch regions via different amino acids. Therefore, SopE represents the first example of a non-Dbl-like protein capable of, inducing guanine nucleotide exchange in Rho family proteins.

About this Structure

1GZS is a Protein complex structure of sequences from Homo sapiens and Salmonella typhimurium with SO4 as ligand. Known structural/functional Site: . Full crystallographic information is available from OCA.

Reference

Structural basis for the reversible activation of a Rho protein by the bacterial toxin SopE., Buchwald G, Friebel A, Galan JE, Hardt WD, Wittinghofer A, Scheffzek K, EMBO J. 2002 Jul 1;21(13):3286-95. PMID:12093730

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