Figure 7.

Structural comparison of Salmonella hook and rod and Campylobacter hook. The Cα ribbon models of Salmonella hook at the top, the rod in the middle, and Campylobacter hook at the bottom. The models are presented in the end-on and side views in the left and right panels, respectively, with only D0-Dc and D1 domains being shown for both hook structures. The Dc domains are highlighted in the left panels by different colors, and the D1 domains are also colored in the right panels. The gaps between the D1 domains are clear in the Salmonella hook structure at the top right, but the gaps are filled by the tip of the β-hairpin of domain Dc in the Salmonella rod and Campylobacter hook structures, further stabilizing and rigidifying their tubular structures.