Confined Mobility of TonB and FepA in Escherichia coli Membranes
| Autor: | Markus A. Lill, Yoriko Lill, Lorne D. Jordan, Ken Ritchie, Phillip E. Klebba, Chuck R. Smallwood, Salete M. C. Newton |
|---|---|
| Rok vydání: | 2016 |
| Předmět: |
0301 basic medicine
Statistical methods Physiology Cell Membranes lcsh:Medicine Mechanical Treatment of Specimens Diffusion Cell membrane Medicine and Health Sciences FepA Ferric-enterobactin transport lcsh:Science Cell Disruption Cytoskeleton Mass Diffusivity Membrane potential Multidisciplinary Chemistry Escherichia coli Proteins Physics Simulation and Modeling Single Molecule Imaging Monte Carlo method Electrophysiology Protein Transport medicine.anatomical_structure Membrane Specimen Disruption Physical Sciences Cellular Structures and Organelles Bacterial outer membrane Bacterial Outer Membrane Proteins Protein Binding Research Article Imaging Techniques 030106 microbiology Geometry Receptors Cell Surface Statistics (mathematics) Molecular Dynamics Simulation Research and Analysis Methods Time-Lapse Imaging Membrane Potential 03 medical and health sciences Fluorescence Imaging Escherichia coli medicine Inner membrane Chemical Physics Cell Membrane lcsh:R Membrane Proteins Biology and Life Sciences Gene Expression Regulation Bacterial Cell Biology Outer Membrane Proteins Antibodies Neutralizing 030104 developmental biology Radii Membrane protein Specimen Preparation and Treatment Biophysics Mathematical and statistical techniques lcsh:Q Carrier Proteins Gene Deletion Mathematics |
| Zdroj: | PLoS ONE, Vol 11, Iss 12, p e0160862 (2016) PLoS ONE |
| ISSN: | 1932-6203 |
| DOI: | 10.1371/journal.pone.0160862 |
| Popis: | The important process of nutrient uptake in Escherichia coli, in many cases, involves transit of the nutrient through a class of beta-barrel proteins in the outer membrane known as TonB-dependent transporters (TBDTs) and requires interaction with the inner membrane protein TonB. Here we have imaged the mobility of the ferric enterobactin transporter FepA and TonB by tracking them in the membranes of live E. coli with single-molecule resolution at time-scales ranging from milliseconds to seconds. We employed simple simulations to model/analyze the lateral diffusion in the membranes of E.coli, to take into account both the highly curved geometry of the cell and artifactual effects expected due to finite exposure time imaging. We find that both molecules perform confined lateral diffusion in their respective membranes in the absence of ligand with FepA confined to a region [Formula: see text] μm in radius in the outer membrane and TonB confined to a region [Formula: see text] μm in radius in the inner membrane. The diffusion coefficient of these molecules on millisecond time-scales was estimated to be [Formula: see text] μm2/s and [Formula: see text] μm2/s for FepA and TonB, respectively, implying that each molecule is free to diffuse within its domain. Disruption of the inner membrane potential, deletion of ExbB/D from the inner membrane, presence of ligand or antibody to FepA and disruption of the MreB cytoskeleton was all found to further restrict the mobility of both molecules. Results are analyzed in terms of changes in confinement size and interactions between the two proteins. |
| Databáze: | OpenAIRE |
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