Activator for both CDC42 and RAC1 by directly interacting with these Rho GTPases and acting as a guanine nucleotide exchange factor (GEF). This activation results in actin cytoskeleton rearrangements and stimulates membrane ruffling, thus promoting bacterial entry into non-phagocytic cells (By similarity). Monomer. Interacts with human CDC42 (By similarity). Secreted via the bsa type III secretion system. Belongs to the GEF (guanine exchange factor) SopE family.