Structure and assembly of Yersinia pestis F1 antigen

Most Gram negative pathogens express surface located fibrillar organelles that are used for adhesion to host epithelia and/or for protection. The assembly of many such organelles is managed by a highly conserved periplasmic chaperone/usher assembly pathway. During the last few years, considerable progress has been made in understanding how periplasmic chaperones mediate folding, targeting, and assembly of F1 antigen subunits into the F1 capsular antigen. In particular, structures representing snapshots of several of the steps involved in assembly have allowed us to begin to draw a detailed molecular-level picture of F1 assembly specifically, and of chaperone/usher-mediated assembly in general. Here, a brief summary of these new results will be presented.