Structure of the <i>N. meningitidis</i> PilQ N0/N1 domains.

<p>A) Structure of the N0 domain (NmPilQ^343–442), ribbon plot (above and structural ensemble (below); for clarity flexible residues 431–442 are omitted. The dashed circle indicates the proposed linker region. B) A composite model for the N0/N1 double domain structure (N0N1PilQ^343–545), is shown with a indigo-green gradient from N- to C-terminus. The model is based on the NMR-derived structure for the first domain, and a CS-ROSETTA <a href="http://www.plospathogens.org/article/info:doi/10.1371/journal.ppat.1002923#ppat.1002923-Shen2" target="_blank">[65]</a> model for the second domain and linker, with the relative orientation of the domains selected from optimal fit to the cryoelectron microscopy density map. The topology of the N0/N1 domains is outlined below, generated using TOPDRAW <a href="http://www.plospathogens.org/article/info:doi/10.1371/journal.ppat.1002923#ppat.1002923-Bond1" target="_blank">[62]</a>.