Fig. 7: Model of the LPS-dependent interspecific OMV recruitment mechanism.

Under iron-deficient conditions, the Fur-repressed T6SS1 gene cluster is de-repressed and secretes the LPS-binding effector TeoL. After secretion by T6SS1, TeoL binds to LPS on the outer leaflet of OMVs (derived from related/unrelated species) and remains at the surface and further binds CubA and CstR on the surface of recipient cells, which tethers OMVs to the recipient cells. Cargos in the OMVs are delivered into recipient cells by a yet unidentified mechanism. OM outer membrane, IM inner membrane, PG peptidoglycan.