7SZO

Structure of a bacterial fimbrial tip containing FocH

Summary for 7SZO

• Entry DOI: 10.2210/pdb7szo/pdb
• Descriptor: Chaperone protein FimC, FimF protein, FimG, ... (6 entities in total)
• Functional Keywords: fimbria, cell adhesion, foch
• Biological source: Escherichia coli; More
• Total number of polymer chains: 10
• Total formula weight: 198095.43

Authors

Stenkamp, R.E.,Le Trong, I.,Aprikian, P.,Sokurenko, E.V. (deposition date: 2021-11-29, release date: 2021-12-29, Last modification date: 2023-10-18)

Primary citation

Thomas, W.E.,Carlucci, L.,Yakovenko, O.,Interlandi, G.,Le Trong, I.,Aprikian, P.,Magala, P.,Larson, L.,Sledneva, Y.,Tchesnokova, V.,Stenkamp, R.E.,Sokurenko, E.V.
Recombinant FimH Adhesin Demonstrates How the Allosteric Catch Bond Mechanism Can Support Fast and Strong Bacterial Attachment in the Absence of Shear.
J.Mol.Biol., 434:167681-167681, 2022

PubMed Abstract: The FimH protein of Escherichia coli is a model two-domain adhesin that is able to mediate an allosteric catch bond mechanism of bacterial cell attachment, where the mannose-binding lectin domain switches from an 'inactive' conformation with fast binding to mannose to an 'active' conformation with slow detachment from mannose. Because mechanical tensile force favors separation of the domains and, thus, FimH activation, it has been thought that the catch bonds can only be manifested in a fluidic shear-dependent mode of adhesion. Here, we used recombinant FimH variants with a weakened inter-domain interaction and show that a fast and sustained allosteric activation of FimH can also occur under static, non-shear conditions. Moreover, it appears that lectin domain conformational activation happens intrinsically at a constant rate, independently from its ability to interact with the pilin domain or mannose. However, the latter two factors control the rate of FimH deactivation. Thus, the allosteric catch bond mechanism can be a much broader phenomenon involved in both fast and strong cell-pathogen attachments under a broad range of hydrodynamic conditions. This concept that allostery can enable more effective receptor-ligand interactions is fundamentally different from the conventional wisdom that allostery provides a mechanism to turn binding off under specific conditions.

PubMed: 35697293
DOI: 10.1016/j.jmb.2022.167681

Experimental method

X-RAY DIFFRACTION (2.8 Å)