Crystal structure of the FimD usher bound to its cognate FimC-FimH substrate.

TitleCrystal structure of the FimD usher bound to its cognate FimC-FimH substrate.
Publication TypeJournal Article
Year of Publication2011
AuthorsPhan, G., H. Remaut, T. Wang, W. J. Allen, K. F. Pirker, A. Lebedev, N. S. Henderson, S. Geibel, E. Volkan, J. Yan, M. B. A. Kunze, J. S. Pinkner, B. Ford, C. W. M. Kay, H. Li, S. J. Hultgren, D. G. Thanassi, and G. Waksman
Date Published2011 Jun 2
Type of Articlesmm
KeywordsAdhesins, Escherichia coli, Crystallization, Escherichia coli Proteins, Fimbriae Proteins, Models, Molecular, Protein Binding, Protein Structure, Quaternary

Type 1 pili are the archetypal representative of a widespread class of adhesive multisubunit fibres in Gram-negative bacteria. During pilus assembly, subunits dock as chaperone-bound complexes to an usher, which catalyses their polymerization and mediates pilus translocation across the outer membrane. Here we report the crystal structure of the full-length FimD usher bound to the FimC-FimH chaperone-adhesin complex and that of the unbound form of the FimD translocation domain. The FimD-FimC-FimH structure shows FimH inserted inside the FimD 24-stranded β-barrel translocation channel. FimC-FimH is held in place through interactions with the two carboxy-terminal periplasmic domains of FimD, a binding mode confirmed in solution by electron paramagnetic resonance spectroscopy. To accommodate FimH, the usher plug domain is displaced from the barrel lumen to the periplasm, concomitant with a marked conformational change in the β-barrel. The amino-terminal domain of FimD is observed in an ideal position to catalyse incorporation of a newly recruited chaperone-subunit complex. The FimD-FimC-FimH structure provides unique insights into the pilus subunit incorporation cycle, and captures the first view of a protein transporter in the act of secreting its cognate substrate.

Alternate JournalNature
PubMed ID21637253
PubMed Central IDPMC3162478
Grant List29549 / / PHS HHS / United States
48689 / / PHS HHS / United States
49950 / / PHS HHS / United States
85602 / / Medical Research Council / United Kingdom
G0100442 / / Medical Research Council / United Kingdom
G0100442(58149) / / Medical Research Council / United Kingdom
GM62987 / GM / NIGMS NIH HHS / United States
GM74985 / GM / NIGMS NIH HHS / United States
P30 EB009998 / EB / NIBIB NIH HHS / United States
R01 GM062987 / GM / NIGMS NIH HHS / United States
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