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- PDB-7oo8: Mechanosensitive channel MscS solubilized with LMNG in closed con... -
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Open data
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Basic information
Entry | Database: PDB / ID: 7oo8 | |||||||||
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Title | Mechanosensitive channel MscS solubilized with LMNG in closed conformation with added lipid | |||||||||
![]() | Mechanosensitive channel of small conductance (MscS) | |||||||||
![]() | MEMBRANE PROTEIN / mechanosensitive channel / LMNG / delipidation | |||||||||
Function / homology | ![]() | |||||||||
Biological species | ![]() ![]() | |||||||||
Method | ELECTRON MICROSCOPY / single particle reconstruction / cryo EM / Resolution: 3.7 Å | |||||||||
![]() | Rasmussen, T. / Flegler, V.J. / Boettcher, B. | |||||||||
Funding support | ![]()
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![]() | ![]() Title: Mechanosensitive channel gating by delipidation. Authors: Vanessa Judith Flegler / Akiko Rasmussen / Karina Borbil / Lea Boten / Hsuan-Ai Chen / Hanna Deinlein / Julia Halang / Kristin Hellmanzik / Jessica Löffler / Vanessa Schmidt / Cihan Makbul ...Authors: Vanessa Judith Flegler / Akiko Rasmussen / Karina Borbil / Lea Boten / Hsuan-Ai Chen / Hanna Deinlein / Julia Halang / Kristin Hellmanzik / Jessica Löffler / Vanessa Schmidt / Cihan Makbul / Christian Kraft / Rainer Hedrich / Tim Rasmussen / Bettina Böttcher / ![]() Abstract: The mechanosensitive channel of small conductance (MscS) protects bacteria against hypoosmotic shock. It can sense the tension in the surrounding membrane and releases solutes if the pressure in the ...The mechanosensitive channel of small conductance (MscS) protects bacteria against hypoosmotic shock. It can sense the tension in the surrounding membrane and releases solutes if the pressure in the cell is getting too high. The membrane contacts MscS at sensor paddles, but lipids also leave the membrane and move along grooves between the paddles to reside as far as 15 Å away from the membrane in hydrophobic pockets. One sensing model suggests that a higher tension pulls lipids from the grooves back to the membrane, which triggers gating. However, it is still unclear to what degree this model accounts for sensing and what contribution the direct interaction of the membrane with the channel has. Here, we show that MscS opens when it is sufficiently delipidated by incubation with the detergent dodecyl-β-maltoside or the branched detergent lauryl maltose neopentyl glycol. After addition of detergent-solubilized lipids, it closes again. These results support the model that lipid extrusion causes gating: Lipids are slowly removed from the grooves and pockets by the incubation with detergent, which triggers opening. Addition of lipids in micelles allows lipids to migrate back into the pockets, which closes the channel even in the absence of a membrane. Based on the distribution of the aliphatic chains in the open and closed conformation, we propose that during gating, lipids leave the complex on the cytosolic leaflet at the height of highest lateral tension, while on the periplasmic side, lipids flow into gaps, which open between transmembrane helices. | |||||||||
History |
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Structure visualization
Movie |
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Structure viewer | Molecule: ![]() ![]() |
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Downloads & links
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Download
PDBx/mmCIF format | ![]() | 302.7 KB | Display | ![]() |
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PDB format | ![]() | 249.4 KB | Display | ![]() |
PDBx/mmJSON format | ![]() | Tree view | ![]() | |
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-Validation report
Arichive directory | ![]() ![]() | HTTPS FTP |
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-Related structure data
Related structure data | ![]() 13007MC ![]() 7onjC ![]() 7onlC ![]() 7oo0C ![]() 7oo6C ![]() 7ooaC C: citing same article ( M: map data used to model this data |
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Similar structure data |
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Links
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Assembly
Deposited unit | ![]()
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Components
#1: Protein | Mass: 31994.039 Da / Num. of mol.: 7 Source method: isolated from a genetically manipulated source Source: (gene. exp.) ![]() ![]() ![]() ![]() |
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-Experimental details
-Experiment
Experiment | Method: ELECTRON MICROSCOPY |
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EM experiment | Aggregation state: PARTICLE / 3D reconstruction method: single particle reconstruction |
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Sample preparation
Component | Name: homoheptameric complex of MscS coordinated with lipids and detergents DDM and LMNG Type: COMPLEX / Entity ID: all / Source: RECOMBINANT | |||||||||||||||||||||||||
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Molecular weight | Value: 0.224 MDa / Experimental value: NO | |||||||||||||||||||||||||
Source (natural) | Organism: ![]() ![]() | |||||||||||||||||||||||||
Source (recombinant) | Organism: ![]() ![]() | |||||||||||||||||||||||||
Buffer solution | pH: 7.5 | |||||||||||||||||||||||||
Buffer component |
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Specimen | Conc.: 5 mg/ml / Embedding applied: NO / Shadowing applied: NO / Staining applied: NO / Vitrification applied: YES | |||||||||||||||||||||||||
Specimen support | Grid material: COPPER / Grid type: Quantifoil R1.2/1.3 | |||||||||||||||||||||||||
Vitrification | Instrument: FEI VITROBOT MARK IV / Cryogen name: ETHANE / Humidity: 100 % / Chamber temperature: 277 K / Details: 7 sec blotting, blot force +25 |
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Electron microscopy imaging
Experimental equipment | ![]() Model: Titan Krios / Image courtesy: FEI Company |
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Microscopy | Model: FEI TITAN KRIOS |
Electron gun | Electron source: ![]() |
Electron lens | Mode: BRIGHT FIELD / Nominal magnification: 75000 X / Nominal defocus max: 1800 nm / Nominal defocus min: 1000 nm / Cs: 2.7 mm / C2 aperture diameter: 70 µm / Alignment procedure: COMA FREE |
Specimen holder | Cryogen: NITROGEN / Specimen holder model: FEI TITAN KRIOS AUTOGRID HOLDER |
Image recording | Average exposure time: 75 sec. / Electron dose: 80 e/Å2 / Detector mode: INTEGRATING / Film or detector model: FEI FALCON III (4k x 4k) / Num. of grids imaged: 1 / Num. of real images: 3292 |
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Processing
Software | Name: PHENIX / Version: 1.19_4092: / Classification: refinement | ||||||||||||||||||||||||||||||||||||||||||||
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EM software |
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CTF correction | Type: PHASE FLIPPING AND AMPLITUDE CORRECTION | ||||||||||||||||||||||||||||||||||||||||||||
Symmetry | Point symmetry: C7 (7 fold cyclic) | ||||||||||||||||||||||||||||||||||||||||||||
3D reconstruction | Resolution: 3.7 Å / Resolution method: FSC 0.143 CUT-OFF / Num. of particles: 43500 / Algorithm: FOURIER SPACE / Symmetry type: POINT | ||||||||||||||||||||||||||||||||||||||||||||
Atomic model building | Protocol: FLEXIBLE FIT / Space: REAL / Target criteria: WEIGHTED MAP SUM AT ATOM CENTERS | ||||||||||||||||||||||||||||||||||||||||||||
Atomic model building | PDB-ID: 6RLD Accession code: 6RLD / Source name: PDB / Type: experimental model | ||||||||||||||||||||||||||||||||||||||||||||
Refine LS restraints |
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