Guanine nucleotide exchange factor SopE, GEF domain (IPR016019)

Short name: SopE_GEF_dom

Overlapping homologous superfamilies

Domain relationships



The type III secretion system of Gram-negative bacteria is used to transport virulence factors from the pathogen directly into the host cell [PMID: 9618447] 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 [PMID: 9482928]. 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 [PMID: 11316807].

Recently, it has been found that SopE and its protein homologue SopE2 can activate different sets of Rho-GTPases in the host cell [PMID: 11316807]. 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 alpha-helical structure consisting of two three-helix bundles arranged in a lamdba shape [PMID: 12093730, PMID: 15379540].

GO terms

Biological Process

GO:0031532 actin cytoskeleton reorganization
GO:0090630 activation of GTPase activity
GO:0009405 pathogenesis

Molecular Function

GO:0005085 guanyl-nucleotide exchange factor activity

Cellular Component

No terms assigned in this category.

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.