FIG 7.

Schematic model for P. aeruginosa T6SS structure and secretion mechanism. As the TssBC sheath begins formation, TagJ associates with the sheath. TagJ in turns complexes with ClpV, which allows ClpV to associate with the TssBC sheath without any sheath conformational changes. ClpV can thus localize to the T6SS apparatus within a few seconds after the initiation of TssB localization. ClpV then disassembles the TssBC sheath, generating a force similar to that seen in microtubule growth and decay, which is used to deliver effectors to the neighboring cell (20). This is in direct contrast to ClpV and TssBC in the T6SS of V. cholerae, which require a conformational change to bind (4).