title: Structure of a Chaperone-Usher Pilus Reveals the Molecular Basis of Rod Uncoiling.
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.
authors.affiliation: Institute of Structural and Molecular Biology, University College London and Birkbeck, Malet Street, London, WC1E 7HX, UK.
authors.forename: Manuela K
authors.initials: MK
authors.lastname: Hospenthal
authors.affiliation: Institute of Structural and Molecular Biology, University College London and Birkbeck, Malet Street, London, WC1E 7HX, UK.
authors.forename: Adam
authors.initials: A
authors.lastname: Redzej
authors.affiliation: Center for Women's Infectious Disease Research and Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, MO 63011, USA.
authors.forename: Karen
authors.initials: K
authors.lastname: Dodson
authors.affiliation: Institute of Structural and Molecular Biology, University College London and Birkbeck, Malet Street, London, WC1E 7HX, UK.
authors.forename: Marta
authors.initials: M
authors.lastname: Ukleja
authors.affiliation: Department of Biochemistry, University of Washington, Seattle, WA 98105, USA.
authors.forename: Brandon
authors.initials: B
authors.lastname: Frenz
authors.affiliation: Institute of Structural and Molecular Biology, University College London and Birkbeck, Malet Street, London, WC1E 7HX, UK.
authors.forename: Catarina
authors.initials: C
authors.lastname: Rodrigues
authors.affiliation: Center for Women's Infectious Disease Research and Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, MO 63011, USA.
authors.forename: Scott J
authors.initials: SJ
authors.lastname: Hultgren
authors.affiliation: Department of Biochemistry, University of Washington, Seattle, WA 98105, USA.
authors.forename: Frank
authors.initials: F
authors.lastname: DiMaio
authors.affiliation: Department of Biochemistry and Molecular Genetics, University of Virginia, Charlottesville, VA 22901, USA. Electronic address: egelman@virginia.edu.
authors.forename: Edward H
authors.initials: EH
authors.lastname: Egelman
authors.affiliation: Institute of Structural and Molecular Biology, University College London and Birkbeck, Malet Street, London, WC1E 7HX, UK. Electronic address: g.waksman@mail.cryst.bbk.ac.uk.
authors.forename: Gabriel
authors.initials: G
authors.lastname: Waksman
mesh_terms: D020285:Cryoelectron Microscopy; D029968:Escherichia coli Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D010861:Fimbriae, Bacterial / Q000737:chemistry* / Q000378:metabolism; D008958:Models, Molecular; D018832:Molecular Chaperones / Q000378:metabolism; D056689:Uropathogenic Escherichia coli / Q000166:cytology / Q000378:metabolism*
chemical_list: D029968:Escherichia coli Proteins; D018832:Molecular Chaperones