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Open data
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Basic information
| Entry | Database: PDB / ID: 28jr | ||||||||||||||||||||||||
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| Title | Encounter Complex: BAM bound BepA | ||||||||||||||||||||||||
Components |
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Keywords | MEMBRANE PROTEIN / Metalloprotease / Outer membrane protein / Complex | ||||||||||||||||||||||||
| Function / homology | Function and homology informationBam protein complex / Gram-negative-bacterium-type cell outer membrane assembly / Hydrolases; Acting on peptide bonds (peptidases) / protein disulfide isomerase activity / protein insertion into membrane / Secretion of toxins / : / cell outer membrane / metalloendopeptidase activity / outer membrane-bounded periplasmic space ...Bam protein complex / Gram-negative-bacterium-type cell outer membrane assembly / Hydrolases; Acting on peptide bonds (peptidases) / protein disulfide isomerase activity / protein insertion into membrane / Secretion of toxins / : / cell outer membrane / metalloendopeptidase activity / outer membrane-bounded periplasmic space / protein-folding chaperone binding / protein-macromolecule adaptor activity / cell adhesion / response to antibiotic / cell surface / zinc ion binding / membrane / metal ion binding / identical protein binding Similarity search - Function | ||||||||||||||||||||||||
| Biological species | ![]() | ||||||||||||||||||||||||
| Method | ELECTRON MICROSCOPY / single particle reconstruction / cryo EM / Resolution: 5.3 Å | ||||||||||||||||||||||||
Authors | Fenn, K.L. / Ranson, N.A. | ||||||||||||||||||||||||
| Funding support | United Kingdom, 1items
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Citation | Journal: Nat Commun / Year: 2026Title: BAM-BepA complexes in outer membrane protein quality control. Authors: Katherine L Fenn / Victoria Higgins / Jonathan M Machin / Antonio N Calabrese / Alan Berry / Sheena E Radford / Neil A Ranson / ![]() Abstract: Correct folding of outer membrane proteins (OMPs) by the β-barrel assembly machinery (BAM) is essential for maintaining the outer membrane (OM) barrier function of diderm bacteria. When OMP ...Correct folding of outer membrane proteins (OMPs) by the β-barrel assembly machinery (BAM) is essential for maintaining the outer membrane (OM) barrier function of diderm bacteria. When OMP biogenesis is perturbed, the β-barrel assembly enhancing protease A (BepA) binds to BAM to mediate quality control, but how BepA interacts with BAM and degrades substrate OMPs remains unclear. Here, cryoEM structures of BAM-bound BepA reveals that BepA induces large conformational changes in the BAM complex enabling the enzyme to poise its active site within the periplasmic ring of BAM, beneath the BamA barrel. The lid of BepA is dynamic, embedding two of its water-soluble helices deep into the membrane bilayer when BAM-bound, which readies BepA for proteolysis of misfolding OMPs. Movement of BepA's plug is triggered by OMP binding rather than interaction with BAM, activating the enzyme for cleavage. We reveal BepA preferentially recognises Aromatic-X-Aromatic (Ar-X-Ar) motifs which are enriched in OMP sequences. The results reveal a mechanism for proteolytic degradation by BepA in OMP quality control which requires interaction with BAM, the membrane, and its OMP substrates. | ||||||||||||||||||||||||
| History |
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Structure visualization
| Structure viewer | Molecule: Molmil Jmol/JSmol |
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Downloads & links
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Download
| PDBx/mmCIF format | 28jr.cif.gz | 389.6 KB | Display | PDBx/mmCIF format |
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| PDB format | pdb28jr.ent.gz | 292.6 KB | Display | PDB format |
| PDBx/mmJSON format | 28jr.json.gz | Tree view | PDBx/mmJSON format | |
| Others | Other downloads |
-Validation report
| Arichive directory | https://data.pdbj.org/pub/pdb/validation_reports/8j/28jr ftp://data.pdbj.org/pub/pdb/validation_reports/8j/28jr | HTTPS FTP |
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-Related structure data
| Related structure data | ![]() 56550 ![]() 56543 ![]() 56549 ![]() 56559 ![]() 28jlC ![]() 28jqC ![]() 28juC C: citing same article ( M: map data used to model this data |
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| Similar structure data | Similarity search - Function & homology F&H Search |
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Links
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Assembly
| Deposited unit | ![]()
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Components
-Outer membrane protein assembly factor ... , 5 types, 5 molecules CDEAB
| #1: Protein | Mass: 34401.250 Da / Num. of mol.: 1 Source method: isolated from a genetically manipulated source Source: (gene. exp.) ![]() ![]() |
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| #2: Protein | Mass: 25816.818 Da / Num. of mol.: 1 Source method: isolated from a genetically manipulated source Source: (gene. exp.) ![]() ![]() |
| #3: Protein | Mass: 11610.833 Da / Num. of mol.: 1 Source method: isolated from a genetically manipulated source Source: (gene. exp.) ![]() ![]() |
| #4: Protein | Mass: 88514.742 Da / Num. of mol.: 1 Source method: isolated from a genetically manipulated source Source: (gene. exp.) ![]() ![]() |
| #5: Protein | Mass: 39882.375 Da / Num. of mol.: 1 Source method: isolated from a genetically manipulated source Source: (gene. exp.) ![]() ![]() |
-Protein / Non-polymers , 2 types, 2 molecules F

| #6: Protein | Mass: 54248.516 Da / Num. of mol.: 1 Source method: isolated from a genetically manipulated source Source: (gene. exp.) ![]() ![]() References: UniProt: P66948, Hydrolases; Acting on peptide bonds (peptidases) |
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| #7: Chemical | ChemComp-ZN / |
-Details
| Has ligand of interest | Y |
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| Has protein modification | N |
-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: BAM BepA / Type: COMPLEX / Details: The BAM complex bound to BepA / Entity ID: #4-#5, #1-#3, #6 / Source: RECOMBINANT |
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| Molecular weight | Value: 0.25 MDa / Experimental value: NO |
| Source (natural) | Organism: ![]() |
| Source (recombinant) | Organism: ![]() |
| Buffer solution | pH: 8 |
| Specimen | Conc.: 3 mg/ml / Embedding applied: NO / Shadowing applied: NO / Staining applied: NO / Vitrification applied: YES / Details: Buffer: 20mM Tris pH 8, 150mM NaCl, 0.05% DDM |
| Vitrification | Instrument: FEI VITROBOT MARK IV / Cryogen name: ETHANE / Humidity: 90 % / Chamber temperature: 278 K |
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Electron microscopy imaging
| Experimental equipment | ![]() Model: Titan Krios / Image courtesy: FEI Company |
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| Microscopy | Model: TFS KRIOS |
| Electron gun | Electron source: FIELD EMISSION GUN / Accelerating voltage: 300 kV / Illumination mode: FLOOD BEAM |
| Electron lens | Mode: BRIGHT FIELD / Nominal defocus max: 3000 nm / Nominal defocus min: 900 nm |
| Specimen holder | Cryogen: NITROGEN / Specimen holder model: FEI TITAN KRIOS AUTOGRID HOLDER |
| Image recording | Electron dose: 40 e/Å2 / Film or detector model: TFS FALCON 4i (4k x 4k) |
| EM imaging optics | Energyfilter name: TFS Selectris / Energyfilter slit width: 10 eV |
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Processing
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| CTF correction | Type: PHASE FLIPPING AND AMPLITUDE CORRECTION | ||||||||||||||||||||||||||||
| Particle selection | Num. of particles selected: 6600000 | ||||||||||||||||||||||||||||
| 3D reconstruction | Resolution: 5.3 Å / Resolution method: FSC 0.143 CUT-OFF / Num. of particles: 8000 / Symmetry type: POINT | ||||||||||||||||||||||||||||
| Atomic model building | Protocol: RIGID BODY FIT | ||||||||||||||||||||||||||||
| Atomic model building | 3D fitting-ID: 1
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About Yorodumi






United Kingdom, 1items
Citation



PDBj






FIELD EMISSION GUN
