ArticleProceedings of the National Academy of Sciences of the United States of America2009
Reconstitution of bacterial outer membrane TonB-dependent transporters in planar lipid bilayer membranes.
Article in Proceedings of the National Academy of Sciences of the United States of America, 2009. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 23 papers.
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Who cites it
23 citing papers in PubMed, 33 citations in OpenAlex.
- Microbial Interactions Shape Spatial Organisation and Transcriptional Responses in a Model Mixed-Species Biofilm.Microbial ecology · 2026Article
- Advances in understanding Ton and Tol system motor proteins.Biochemical Society transactions · 2026Review
- The Name Is Barrel, β-Barrel.Methods in molecular biology (Clifton, N.J.) · 2024Article
- Gating of β-Barrel Protein Pores, Porins, and Channels: An Old Problem with New Facets.International journal of molecular sciences · 2023Review
- Siderophore conjugates to combat antibiotic-resistant bacteria.RSC medicinal chemistry · 2023Review
- A modular spring-loaded actuator for mechanical activation of membrane proteins.Nature communications · 2022Article
- Ton motor complexes.Current opinion in structural biology · 2021Review
- Structure and Stoichiometry of the Ton Molecular Motor.International journal of molecular sciences · 2020Review
- Article
- Aberrantly Large Single-Channel Conductance of Polyhistidine Arm-Containing Protein Nanopores.Biochemistry · 2017Article
- A new class of hybrid secretion system is employed in Pseudomonas amyloid biogenesis.Nature communications · 2017Article
- Interrogating Detergent Desolvation of Nanopore-Forming Proteins by Fluorescence Polarization Spectroscopy.Analytical chemistry · 2017Article
- Going Outside the TonB Box: Identification of Novel FepA-TonB InteractionsJournal of bacteriology · 2017Article
- Global redesign of a native β-barrel scaffold.Biochimica et biophysica acta · 2016Article
- Ion conductance of the stem of the anthrax toxin channel during lethal factor translocation.Journal of molecular biology · 2015Article
- Structure of the atypical bacteriocin pectocin M2 implies a novel mechanism of protein uptake.Molecular microbiology · 2014Article
- The unstructured domain of colicin N kills Escherichia coli.Molecular microbiology · 2013Article
- Article
- TonB-dependent transporter FhuA in planar lipid bilayers: partial exit of its plug from the barrel.Biochemistry · 2012Article
- The N-terminal domain of a TonB-dependent transporter undergoes a reversible stepwise denaturation.Biochemistry · 2012Article
Corrections and comments
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Authors and funding
7 authors at 4 institutions in 2 countries.
Funding
Abstract
Micronutrients such as siderophore-bound iron and vitamin B(12) cross the outer membrane of gram-negative bacteria through a group of 22-stranded beta-barrel proteins. They share the unusual feature that their N-terminal end inserts from the periplasmic side into the beta-barrel and plugs the lumen. Transport results from energy-driven movement of TonB protein, which either pulls the plug out of the barrel or causes it to rearrange within the barrel. Attempts to reconstitute native plugged channels in an ion-conducting state in lipid bilayer membranes have so far been unsuccessful. We, however, have discovered that if the cis solution contained 4 M urea, then, with the periplasmic side of the channel facing that solution, macroscopic conductances and single channel events could be observed. These results were obtained with FhuA, Cir, and BtuB; for the former two, the channels were closed by removing the 4 M urea. Channels generated by 4 M urea exposure were not a consequence of general protein denaturation, as their ligand-binding properties were preserved. Thus, with FhuA, addition of ferrichrome (its siderophore) to the trans, extracellular-facing side reversibly inhibited 4 M urea-induced channel opening and blocked the channels. With Cir, addition of colicin Ia (the microbial toxin that targets Cir) to the trans, extracellular-facing side prevented 4 M urea-induced channel opening. We hypothesize that 4 M urea reversibly unfolds the FhuA and Cir plugs, thereby opening an ion-conducting pathway through these channels, and that this mimics to some extent the in vivo action of TonB on these plugs.
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Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.