Structure of a Chaperone-Usher Pilus Reveals the Molecular Basis of Rod Uncoiling.
Hospenthal, M.K., Redzej, A., Dodson, K., Ukleja, M., Frenz, B., Rodrigues, C., Hultgren, S.J., Dimaio, F., Egelman, E.H., Waksman, G.(2016) Cell 164: 269
- PubMed: 26724865 
- DOI: https://doi.org/10.1016/j.cell.2015.11.049
- Primary Citation of Related Structures:  
5FLU - PubMed Abstract: 
Types 1 and P pili are prototypical bacterial cell-surface appendages playing essential roles in mediating adhesion of bacteria to the urinary tract. These pili, assembled by the chaperone-usher pathway, are polymers of pilus subunits assembling into two parts: a thin, short tip fibrillum at the top, mounted on a long pilus rod. The rod adopts a helical quaternary structure and is thought to play essential roles: its formation may drive pilus extrusion by preventing backsliding of the nascent growing pilus within the secretion pore; the rod also has striking spring-like properties, being able to uncoil and recoil depending on the intensity of shear forces generated by urine flow. Here, we present an atomic model of the P pilus generated from a 3.8 Å resolution cryo-electron microscopy reconstruction. This structure provides the molecular basis for the rod's remarkable mechanical properties and illuminates its role in pilus secretion.
Organizational Affiliation: 
Institute of Structural and Molecular Biology, University College London and Birkbeck, Malet Street, London, WC1E 7HX, UK.