+Open data
-Basic information
Entry | Database: PDB / ID: 7nb6 | ||||||
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Title | Structure of the autoinducer-2 exporter TqsA from E. coli | ||||||
Components | AI-2 transport protein TqsA | ||||||
Keywords | STRUCTURAL PROTEIN / cryo-EM / membrane protein / autoinducer-2 exporter / quorum sensing / pentamer / protein oligomerization | ||||||
Function / homology | autoinducer AI-2 transmembrane transport / Transmembrane protein TqsA-like / AI-2E family transporter / quorum sensing / plasma membrane => GO:0005886 / efflux transmembrane transporter activity / transmembrane transport / AI-2 transport protein TqsA Function and homology information | ||||||
Biological species | Escherichia coli (E. coli) | ||||||
Method | ELECTRON MICROSCOPY / single particle reconstruction / cryo EM / Resolution: 3.3 Å | ||||||
Authors | Khera, R. / Xie, H. / Michel, H. | ||||||
Funding support | Germany, 1items
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Citation | Journal: EMBO J / Year: 2022 Title: Cryo-EM structures of pentameric autoinducer-2 exporter from Escherichia coli reveal its transport mechanism. Authors: Radhika Khera / Ahmad R Mehdipour / Jani R Bolla / Joerg Kahnt / Sonja Welsch / Ulrich Ermler / Cornelia Muenke / Carol V Robinson / Gerhard Hummer / Hao Xie / Hartmut Michel / Abstract: Bacteria utilize small extracellular molecules to communicate in order to collectively coordinate their behaviors in response to the population density. Autoinducer-2 (AI-2), a universal molecule for ...Bacteria utilize small extracellular molecules to communicate in order to collectively coordinate their behaviors in response to the population density. Autoinducer-2 (AI-2), a universal molecule for both intra- and inter-species communication, is involved in the regulation of biofilm formation, virulence, motility, chemotaxis, and antibiotic resistance. While many studies have been devoted to understanding the biosynthesis and sensing of AI-2, very little information is available on its export. The protein TqsA from Escherichia coli, which belongs to the AI-2 exporter superfamily, has been shown to export AI-2. Here, we report the cryogenic electron microscopic structures of two AI-2 exporters (TqsA and YdiK) from E. coli at 3.35 Å and 2.80 Å resolutions, respectively. Our structures suggest that the AI-2 exporter exists as a homo-pentameric complex. In silico molecular docking and native mass spectrometry experiments were employed to demonstrate the interaction between AI-2 and TqsA, and the results highlight the functional importance of two helical hairpins in substrate binding. We propose that each monomer works as an independent functional unit utilizing an elevator-type transport mechanism. | ||||||
History |
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-Structure visualization
Structure viewer | Molecule: MolmilJmol/JSmol |
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-Downloads & links
-Download
PDBx/mmCIF format | 7nb6.cif.gz | 282.8 KB | Display | PDBx/mmCIF format |
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PDB format | pdb7nb6.ent.gz | 234.1 KB | Display | PDB format |
PDBx/mmJSON format | 7nb6.json.gz | Tree view | PDBx/mmJSON format | |
Others | Other downloads |
-Validation report
Summary document | 7nb6_validation.pdf.gz | 1.1 MB | Display | wwPDB validaton report |
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Full document | 7nb6_full_validation.pdf.gz | 1.2 MB | Display | |
Data in XML | 7nb6_validation.xml.gz | 61 KB | Display | |
Data in CIF | 7nb6_validation.cif.gz | 85.4 KB | Display | |
Arichive directory | https://data.pdbj.org/pub/pdb/validation_reports/nb/7nb6 ftp://data.pdbj.org/pub/pdb/validation_reports/nb/7nb6 | HTTPS FTP |
-Related structure data
Related structure data | 12256MC 7ot9C M: map data used to model this data C: citing same article (ref.) |
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Similar structure data | Similarity search - Function & homologyF&H Search |
-Links
-Assembly
Deposited unit |
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Noncrystallographic symmetry (NCS) | NCS domain:
NCS domain segments:
NCS oper:
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-Components
#1: Protein | Mass: 37563.543 Da / Num. of mol.: 5 Source method: isolated from a genetically manipulated source Source: (gene. exp.) Escherichia coli (strain K12) (bacteria) Strain: K12 / Gene: tqsA, ydgG, b1601, JW1593 / Plasmid: pBADC3 / Production host: Escherichia coli (E. coli) / Strain (production host): Top10 / References: UniProt: P0AFS5 |
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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 |
-Sample preparation
Component | Name: Pentameric TqsA / Type: COMPLEX / Entity ID: all / Source: RECOMBINANT |
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Molecular weight | Value: 0.187 MDa / Experimental value: YES |
Source (natural) | Organism: Escherichia coli (E. coli) |
Source (recombinant) | Organism: Escherichia coli (E. coli) / Plasmid: pBADC3 |
Buffer solution | pH: 7.5 / Details: 50 mM Tris (pH 7.5), 150 mM NaCl and 0.006% GDN |
Specimen | Conc.: 3.4 mg/ml / Embedding applied: NO / Shadowing applied: NO / Staining applied: NO / Vitrification applied: YES Details: Its a membrane protein and for purification, glyco-diosgenin was used. |
Specimen support | Grid material: COPPER / Grid mesh size: 300 divisions/in. / Grid type: C-flat-1.2/1.3 |
Vitrification | Instrument: FEI VITROBOT MARK III / Cryogen name: ETHANE / Humidity: 100 % / Chamber temperature: 277.15 K / Details: blot time 4 s, blot force +20 |
-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: FIELD EMISSION GUN / Accelerating voltage: 300 kV / Illumination mode: OTHER |
Electron lens | Mode: OTHER / Cs: 2.7 mm |
Specimen holder | Cryogen: NITROGEN / Specimen holder model: FEI TITAN KRIOS AUTOGRID HOLDER |
Image recording | Electron dose: 80 e/Å2 / Film or detector model: GATAN K3 BIOQUANTUM (6k x 4k) / Num. of grids imaged: 1 / Num. of real images: 5452 |
Image scans | Width: 5760 / Height: 4092 |
-Processing
Software | Name: PHENIX / Version: 1.18.2_3874: / Classification: refinement | ||||||||||||||||||||||||||||||||||||||||
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EM software |
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CTF correction | Type: PHASE FLIPPING AND AMPLITUDE CORRECTION | ||||||||||||||||||||||||||||||||||||||||
Particle selection | Num. of particles selected: 1218552 | ||||||||||||||||||||||||||||||||||||||||
Symmetry | Point symmetry: C5 (5 fold cyclic) | ||||||||||||||||||||||||||||||||||||||||
3D reconstruction | Resolution: 3.3 Å / Resolution method: FSC 0.143 CUT-OFF / Num. of particles: 141366 / Num. of class averages: 1 / Symmetry type: POINT | ||||||||||||||||||||||||||||||||||||||||
Refinement | Cross valid method: NONE Stereochemistry target values: GeoStd + Monomer Library + CDL v1.2 | ||||||||||||||||||||||||||||||||||||||||
Displacement parameters | Biso mean: 109.91 Å2 | ||||||||||||||||||||||||||||||||||||||||
Refine LS restraints |
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Refine LS restraints NCS |
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