| Type: | Family | Name: | Type III secretion chaperone SycE |
| 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. Yersinia spp. secrete an effector protein called YopE through the type III needle []. This acts as a Rho GTPase-activating protein that disrupts the host cell actin cytoskeleton, and is regulated by a chaperone protein called SycE/YerA []. In the absence of the SycE chaperone, YopE is not transported through the needle and remains in the bacterial cytoplasm, so suggesting a crucial role for this moiety []. Both the YopE regulator and SycE/YerA proteins share similarity with the exoenzyme S (ExoS) gene product of Pseudomonas aeruginosa[]. ExoS has both ADP-ribosylating and GTPase activity, and is implicated as a virulence factor. As type III secretion in Pseudomonas is often associated with systemic and even fatal infections in susceptible patients [], the proteins involved are of interest as vaccine and drug targets. | Short Name: | T3SS_chp_SycE |
