(A), E. chaffeensis orthologs of E. coli T1SS components HlyB (ECH_0383) HlyD (ECH_0970) and TolC (ECH_1020) have been identified. Schematic depicts secretion of T1SS substrates when acidic C-terminal T1S-signals in unfolded cytoplasmic proteins are recognized by inner membrane protein HlyB and in an ATP-dependent manner the substrate is translocated across the inner membrane, then the periplasm via HlyD Substrates pass through TolC, an outer membrane channel and into the extracellular space. (B), Secretion of Ehrlichia TRPs and Ank200 by E. coli in the presence or absence of TolC, and (C), and without (−) and with (+) HlyBD [38]. E. chaffeensis effector secretion is significantly enhanced in the presence of TolC or HlyB/D components of the T1SS.