Molecular mechanism of P pilus termination in uropathogenic Escherichia coli.

TitleMolecular mechanism of P pilus termination in uropathogenic Escherichia coli.
Publication TypeJournal Article
Year of Publication2006
AuthorsVerger, D., E. Miller, H. Remaut, G. Waksman, and S. Hultgren
JournalEMBO Rep
Volume7
Issue12
Pagination1228-32
Date Published2006 Dec
Type of Articlesmm
ISSN1469-221X
KeywordsBacterial Adhesion, Crystallography, X-Ray, Escherichia coli, Escherichia coli Proteins, Fimbriae, Bacterial, Molecular Chaperones, Protein Folding, Protein Structure, Tertiary, Structure-Activity Relationship
Abstract

P pili are important adhesive fibres that are assembled by the conserved chaperone-usher pathway. During pilus assembly, the subunits are incorporated into the growing fibre by the donor-strand exchange mechanism, whereby the beta-strand of the chaperone, which complements the incomplete immunoglobulin fold of each subunit, is displaced by the amino-terminal extension of an incoming subunit in a zip-in-zip-out exchange process that is initiated at the P5 pocket, an exposed hydrophobic pocket in the groove of the subunit. In vivo, termination of P pilus growth requires a specialized subunit, PapH. Here, we show that PapH is incorporated at the base of the growing pilus, where it is unable to undergo donor-strand exchange. This inability is not due to a stronger PapD-PapH interaction, but to a lack of a P5 initiator pocket in the PapH structure, suggesting that PapH terminates pilus growth because it is lacking the initiation point by which donor-strand exchange proceeds.

DOI10.1038/sj.embor.7400833
Alternate JournalEMBO Rep.
PubMed ID17082819
PubMed Central IDPMC1794691