Protein Domain : Guanine nucleotide exchange factor SopE, GEF domain IPR016019

Type	Domain
Description	The type III secretion system of Gram-negative bacteria is used to transport virulence factors from the pathogen directly into the host cell [ ] and is only triggered when the bacterium comes into close contact with the host. Effector proteins secreted by the type III system do not possess a secretion signal, and are considered unique because of this. Salmonella spp. secrete an effector protein called SopE that is responsible for stimulating the reorganisation of the host cell actin cytoskeleton, and ruffling of the cellular membrane []. It acts as a guanyl-nucleotide-exchange factor on Rho-GTPase proteins such as Cdc42 and Rac. As it is imperative for the bacterium to revert the cell back to its "normal"state as quickly as possible, another tyrosine phosphatase effector called SptP reverses the actions brought about by SopE [ ]. Recently, it has been found that SopE and its protein homologue SopE2 can activate different sets of Rho-GTPases in the host cell [ ]. Far from being a redundant set of two similar type III effectors, they both act in unison to specifically activate different Rho-GTPase signalling cascades in the host cell during infection.This entry represents the guanine nucleotide exchange factor domain of SopE. This domain has an α-helical structure consisting of two three-helix bundles arranged in a lamdba shape [ , ].
Short Name	SopE_GEF_dom