Fiber formation across the bacterial outer membrane by the chaperone/usher pathway.

TitleFiber formation across the bacterial outer membrane by the chaperone/usher pathway.
Publication TypeJournal Article
Year of Publication2008
AuthorsRemaut, H., Tang C., Henderson N. S., Pinkner J. S., Wang T., Hultgren S. J., Thanassi D. G., Waksman G., and Li H.
JournalCell
Volume133
Issue4
Pagination640-52
Date Published2008 May 16
Type of Articlesmm
ISSN1097-4172
KeywordsAmino Acid Sequence, Biosynthetic Pathways, Crystallography, X-Ray, Escherichia coli, Escherichia coli Proteins, Fimbriae Proteins, Fimbriae, Bacterial, Models, Molecular, Molecular Chaperones, Molecular Sequence Data, Multiprotein Complexes, Porins
Abstract

Gram-negative pathogens commonly exhibit adhesive pili on their surfaces that mediate specific attachment to the host. A major class of pili is assembled via the chaperone/usher pathway. Here, the structural basis for pilus fiber assembly and secretion performed by the outer membrane assembly platform--the usher--is revealed by the crystal structure of the translocation domain of the P pilus usher PapC and single particle cryo-electron microscopy imaging of the FimD usher bound to a translocating type 1 pilus assembly intermediate. These structures provide molecular snapshots of a twinned-pore translocation machinery in action. Unexpectedly, only one pore is used for secretion, while both usher protomers are used for chaperone-subunit complex recruitment. The translocating pore itself comprises 24 beta strands and is occluded by a folded plug domain, likely gated by a conformationally constrained beta-hairpin. These structures capture the secretion of a virulence factor across the outer membrane of gram-negative bacteria.

DOI10.1016/j.cell.2008.03.033
Alternate JournalCell
PubMed ID18485872
PubMed Central IDPMC3036173
Grant List58149 / / Medical Research Council / United Kingdom
AI029549 / AI / NIAID NIH HHS / United States
AI049950 / AI / NIAID NIH HHS / United States
AI48689 / AI / NIAID NIH HHS / United States
GM062987 / GM / NIGMS NIH HHS / United States
GM074985 / GM / NIGMS NIH HHS / United States
R01 AI048689 / AI / NIAID NIH HHS / United States
R01 AI048689-08 / AI / NIAID NIH HHS / United States
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