Reconstitution of pilus assembly reveals a bacterial outer membrane catalyst.
Type 1 pili from uropathogenic Escherichia coli are a prototype of adhesive surface organelles assembled and secreted by the conserved chaperone/usher pathway. We reconstituted type 1 pilus biogenesis from purified pilus proteins. The usher FimD acted as a catalyst to accelerate the ordered assembly of protein subunits independently of cellular energy. Its activity was highly dependent on the adhesin subunit FimH, which triggered the conversion of FimD into a high-efficiency assembly catalyst. Furthermore, a simple kinetic model adequately rationalized usher-catalyzed pilus assembly in vivo. Our results contribute to a mechanistic understanding of protein-catalyzed biogenesis of supramolecular protein complexes at the bacterial outer cell membrane.
Nishiyama
Mireille
M
Institute of Molecular Biology and Biophysics, Eidgenössische Technische Hochschule (ETH) Zurich, 8093 Zurich, Switzerland.
Ishikawa
Takashi
T
Rechsteiner
Helene
H
Glockshuber
Rudi
R
D018830:Adhesins, Escherichia coli / Q000378:metabolism; D001425:Bacterial Outer Membrane Proteins / Q000378:metabolism*; D002384:Catalysis; D004926:Escherichia coli / Q000378:metabolism* / Q000648:ultrastructure; D029968:Escherichia coli Proteins / Q000235:genetics / Q000378:metabolism*; D036781:Fimbriae Proteins / Q000235:genetics / Q000378:metabolism*; D010861:Fimbriae, Bacterial / Q000378:metabolism* / Q000648:ultrastructure; D007700:Kinetics; D008954:Models, Biological; D013696:Temperature
D018830:Adhesins, Escherichia coli; D001425:Bacterial Outer Membrane Proteins; D029968:Escherichia coli Proteins; C521674:FimF protein, E coli; C489721:fimC protein, E coli; C489283:fimD protein, E coli; C058769:fimH protein, E coli; C063055:fimbrillin; D036781:Fimbriae Proteins