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Structure and function of enterotoxigenic E scherichia coli fimbriae from differing assembly pathways
Author(s) -
Mortezaei Narges,
Epler Chelsea R.,
Shao Paul P.,
Shirdel Mariam,
Singh Bhupender,
McVeigh Annette,
Uhlin Bernt Eric,
Savarino Stephen J.,
Andersson Magnus,
Bullitt Esther
Publication year - 2015
Publication title -
molecular microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.857
H-Index - 247
eISSN - 1365-2958
pISSN - 0950-382X
DOI - 10.1111/mmi.12847
Subject(s) - fimbria , biology , enterotoxigenic escherichia coli , function (biology) , microbiology and biotechnology , fimbriae proteins , pilus , computational biology , escherichia coli , genetics , enterotoxin , gene
Summary Pathogenic enterotoxigenic E scherichia coli ( ETEC ) are the major bacterial cause of diarrhea in young children in developing countries and in travelers, causing significant mortality in children. Adhesive fimbriae are a prime virulence factor for ETEC , initiating colonization of the small intestinal epithelium. Similar to other G ram‐negative bacteria, ETEC express one or more diverse fimbriae, some assembled by the chaperone‐usher pathway and others by the alternate chaperone pathway. Here, we elucidate structural and biophysical aspects and adaptations of each fimbrial type to its respective host niche. CS 20 fimbriae are compared with colonization factor antigen I ( CFA / I ) fimbriae, which are two ETEC fimbriae assembled via different pathways, and with P ‐fimbriae from uropathogenic E . coli . Many fimbriae unwind from their native helical filament to an extended linear conformation under force, thereby sustaining adhesion by reducing load at the point of contact between the bacterium and the target cell. CFA / I fimbriae require the least force to unwind, followed by CS 20 fimbriae and then P ‐fimbriae, which require the highest unwinding force. We conclude from our electron microscopy reconstructions, modeling and force spectroscopy data that the target niche plays a central role in the biophysical properties of fimbriae that are critical for bacterial pathophysiology.