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Open data
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Basic information
Entry | Database: PDB / ID: 8a7q | ||||||||||||
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Title | beta-2-microglobulin V27M amyloid fibril form 4PF | ||||||||||||
![]() | Beta-2-microglobulin | ||||||||||||
![]() | PROTEIN FIBRIL / Amyloid / fibril / helical / cross-beta / dialysis-related amyloidosis / polymorph / b2m | ||||||||||||
Function / homology | ![]() negative regulation of receptor binding / early endosome lumen / Nef mediated downregulation of MHC class I complex cell surface expression / DAP12 interactions / transferrin transport / cellular response to iron ion / Endosomal/Vacuolar pathway / Antigen Presentation: Folding, assembly and peptide loading of class I MHC / peptide antigen assembly with MHC class II protein complex / antigen processing and presentation of exogenous protein antigen via MHC class Ib, TAP-dependent ...negative regulation of receptor binding / early endosome lumen / Nef mediated downregulation of MHC class I complex cell surface expression / DAP12 interactions / transferrin transport / cellular response to iron ion / Endosomal/Vacuolar pathway / Antigen Presentation: Folding, assembly and peptide loading of class I MHC / peptide antigen assembly with MHC class II protein complex / antigen processing and presentation of exogenous protein antigen via MHC class Ib, TAP-dependent / cellular response to iron(III) ion / MHC class II protein complex / negative regulation of forebrain neuron differentiation / ER to Golgi transport vesicle membrane / peptide antigen assembly with MHC class I protein complex / regulation of erythrocyte differentiation / regulation of iron ion transport / response to molecule of bacterial origin / MHC class I peptide loading complex / HFE-transferrin receptor complex / T cell mediated cytotoxicity / antigen processing and presentation of endogenous peptide antigen via MHC class I / positive regulation of T cell cytokine production / antigen processing and presentation of exogenous peptide antigen via MHC class II / positive regulation of immune response / MHC class I protein complex / positive regulation of T cell activation / peptide antigen binding / positive regulation of receptor-mediated endocytosis / negative regulation of neurogenesis / positive regulation of T cell mediated cytotoxicity / cellular response to nicotine / multicellular organismal-level iron ion homeostasis / Modulation by Mtb of host immune system / specific granule lumen / phagocytic vesicle membrane / recycling endosome membrane / Immunoregulatory interactions between a Lymphoid and a non-Lymphoid cell / Interferon gamma signaling / negative regulation of epithelial cell proliferation / MHC class II protein complex binding / late endosome membrane / sensory perception of smell / positive regulation of cellular senescence / tertiary granule lumen / DAP12 signaling / T cell differentiation in thymus / ER-Phagosome pathway / negative regulation of neuron projection development / protein refolding / early endosome membrane / protein homotetramerization / amyloid fibril formation / intracellular iron ion homeostasis / learning or memory / Amyloid fiber formation / endoplasmic reticulum lumen / Golgi membrane / lysosomal membrane / external side of plasma membrane / focal adhesion / Neutrophil degranulation / SARS-CoV-2 activates/modulates innate and adaptive immune responses / structural molecule activity / endoplasmic reticulum / Golgi apparatus / protein homodimerization activity / extracellular space / extracellular exosome / extracellular region / identical protein binding / membrane / plasma membrane / cytosol Similarity search - Function | ||||||||||||
Biological species | ![]() | ||||||||||||
Method | ELECTRON MICROSCOPY / helical reconstruction / cryo EM / Resolution: 2.8 Å | ||||||||||||
![]() | Wilkinson, M. / Gallardo, R. / Radford, S.E. / Ranson, N.A. | ||||||||||||
Funding support | ![]()
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![]() | ![]() Title: Disease-relevant β-microglobulin variants share a common amyloid fold. Authors: Martin Wilkinson / Rodrigo U Gallardo / Roberto Maya Martinez / Nicolas Guthertz / Masatomo So / Liam D Aubrey / Sheena E Radford / Neil A Ranson / ![]() ![]() ![]() Abstract: β-microglobulin (βm) and its truncated variant ΔΝ6 are co-deposited in amyloid fibrils in the joints, causing the disorder dialysis-related amyloidosis (DRA). Point mutations of βm result in ...β-microglobulin (βm) and its truncated variant ΔΝ6 are co-deposited in amyloid fibrils in the joints, causing the disorder dialysis-related amyloidosis (DRA). Point mutations of βm result in diseases with distinct pathologies. βm-D76N causes a rare systemic amyloidosis with protein deposited in the viscera in the absence of renal failure, whilst βm-V27M is associated with renal failure, with amyloid deposits forming predominantly in the tongue. Here we use cryoEM to determine the structures of fibrils formed from these variants under identical conditions in vitro. We show that each fibril sample is polymorphic, with diversity arising from a 'lego-like' assembly of a common amyloid building block. These results suggest a 'many sequences, one amyloid fold' paradigm in contrast with the recently reported 'one sequence, many amyloid folds' behaviour of intrinsically disordered proteins such as tau and Aβ. | ||||||||||||
History |
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Structure visualization
Structure viewer | Molecule: ![]() ![]() |
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Downloads & links
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Download
PDBx/mmCIF format | ![]() | 151.9 KB | Display | ![]() |
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PDB format | ![]() | 120.6 KB | Display | ![]() |
PDBx/mmJSON format | ![]() | Tree view | ![]() | |
Others | ![]() |
-Validation report
Summary document | ![]() | 1.4 MB | Display | ![]() |
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Full document | ![]() | 1.4 MB | Display | |
Data in XML | ![]() | 34.8 KB | Display | |
Data in CIF | ![]() | 51.9 KB | Display | |
Arichive directory | ![]() ![]() | HTTPS FTP |
-Related structure data
Related structure data | ![]() 15224MC ![]() 8a7oC ![]() 8a7pC ![]() 8a7tC C: citing same article ( M: map data used to model this data |
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Similar structure data | Similarity search - Function & homology ![]() |
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Links
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Assembly
Deposited unit | ![]()
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Components
#1: Protein | Mass: 11780.226 Da / Num. of mol.: 12 / Mutation: V27M Source method: isolated from a genetically manipulated source Details: Natural b2m variant V27M / Source: (gene. exp.) ![]() ![]() ![]() Has protein modification | Y | |
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-Experimental details
-Experiment
Experiment | Method: ELECTRON MICROSCOPY |
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EM experiment | Aggregation state: FILAMENT / 3D reconstruction method: helical reconstruction |
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Sample preparation
Component | Name: Amyloid fibril polymorph 2PFa of the beta-2-microglobulin deltaN6 variant. Type: COMPLEX Details: Recombinantly expressed and fibrillated in vitro at pH 6.2 Entity ID: all / Source: RECOMBINANT | |||||||||||||||
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Molecular weight | Experimental value: NO | |||||||||||||||
Source (natural) | Organism: ![]() | |||||||||||||||
Source (recombinant) | Organism: ![]() ![]() | |||||||||||||||
Buffer solution | pH: 6.2 | |||||||||||||||
Buffer component |
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Specimen | Embedding applied: NO / Shadowing applied: NO / Staining applied: NO / Vitrification applied: YES Details: Fibrillation conditions: 20 uM monomeric b2m-V27M at 37C with shaking at 600 rpm for 3-4 weeks | |||||||||||||||
Specimen support | Details: The grid was plasma cleaned prior to 2x application of graphene oxide-DDM mixture, then grid was used immediately for sample application and vitrification Grid material: COPPER / Grid mesh size: 300 divisions/in. / Grid type: Quantifoil R1.2/1.3 | |||||||||||||||
Vitrification | Instrument: FEI VITROBOT MARK IV / Cryogen name: ETHANE / Humidity: 90 % / Chamber temperature: 277 K / Details: 6s blot |
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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: 130000 X / Nominal defocus max: 2500 nm / Nominal defocus min: 1300 nm / Cs: 2.7 mm / C2 aperture diameter: 50 µm / Alignment procedure: COMA FREE |
Specimen holder | Specimen holder model: FEI TITAN KRIOS AUTOGRID HOLDER |
Image recording | Average exposure time: 6 sec. / Electron dose: 43 e/Å2 / Film or detector model: FEI FALCON IV (4k x 4k) / Num. of grids imaged: 1 / Num. of real images: 4079 Details: 1442 raw EER frames were collected per image and combined into 40 fractions for processing |
EM imaging optics | Energyfilter name: TFS Selectris / Energyfilter slit width: 10 eV |
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Processing
EM software |
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CTF correction | Type: PHASE FLIPPING AND AMPLITUDE CORRECTION | ||||||||||||||||||||||||||||||||||||
Helical symmerty | Angular rotation/subunit: -0.73 ° / Axial rise/subunit: 4.85 Å / Axial symmetry: C2 | ||||||||||||||||||||||||||||||||||||
Particle selection | Num. of particles selected: 229692 Details: Manually picked a subset of images to train a model for automatic fibril segment picking in crYOLO | ||||||||||||||||||||||||||||||||||||
3D reconstruction | Resolution: 2.8 Å / Resolution method: FSC 0.143 CUT-OFF / Num. of particles: 4732 / Symmetry type: HELICAL | ||||||||||||||||||||||||||||||||||||
Atomic model building | B value: 44 / Protocol: AB INITIO MODEL / Space: REAL |