AvrE (DspE) of 1838 aas and a beta (β) structure after secretion from the bacteriial cytoplasm via a type III protein secretion system (TC# 3.A.6) into the host cell and insertion into the plasma membrane of the plant cell where it transports metabolites, water and small molecules such as fluorescene dyes (Nomura et al. 2023).  DspE in Xenopus oocytes resulted in inward and outward currents, permeability to water and osmolarity-dependent oocyte swelling and bursting. Liposome reconstitution confirmed that the DspE channel alone is sufficient to allow the passage of small molecules such as fluorescein dye. Targeted screening of chemical blockers based on the predicted pore size (15-20 Å) of the DspE channel identified polyamidoamine dendrimers as inhibitors of the DspE/AvrE channels. Notably, polyamidoamines broadly inhibit AvrE and DspE virulence activities in Xenopus oocytes and during E. amylovora and P. syringae infections.