Figure 7: Position of TssC N-terminal helix in the contracted and extended T6SS sheath models.

(A) Contracted V. cholerae VipAB sheath atomic structure24 (right, top view; left, side view). Four sheath rows are shown (right, top view; left, side view). The red arrows indicate the VipB (TssC) first visible residue. (B) Extended V. cholerae VipAB sheath molecular model. The inset shows a close-up of the VipB N-terminus and the flanking cavity (surligned in red) that could accommodate the VipB 1-60 fragment.