+
Open data
-
Basic information
Entry | Database: PDB / ID: 6gk3 | ||||||||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Title | Two protofilament beta-2-microglobulin amyloid fibril | ||||||||||||||||||
![]() | Beta-2-microglobulin | ||||||||||||||||||
![]() | PROTEIN FIBRIL / amyloid / b2m | ||||||||||||||||||
Function / homology | ![]() positive regulation of ferrous iron binding / positive regulation of transferrin receptor binding / positive regulation of receptor binding / early endosome lumen / Nef mediated downregulation of MHC class I complex cell surface expression / DAP12 interactions / negative regulation of receptor binding / cellular response to iron ion / Endosomal/Vacuolar pathway / Antigen Presentation: Folding, assembly and peptide loading of class I MHC ...positive regulation of ferrous iron binding / positive regulation of transferrin receptor binding / positive regulation of receptor binding / early endosome lumen / Nef mediated downregulation of MHC class I complex cell surface expression / DAP12 interactions / negative regulation of receptor binding / cellular response to iron ion / Endosomal/Vacuolar pathway / Antigen Presentation: Folding, assembly and peptide loading of class I MHC / cellular response to iron(III) ion / antigen processing and presentation of exogenous protein antigen via MHC class Ib, TAP-dependent / negative regulation of forebrain neuron differentiation / regulation of erythrocyte differentiation / ER to Golgi transport vesicle membrane / peptide antigen assembly with MHC class I protein complex / 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 / MHC class I protein complex / multicellular organismal-level iron ion homeostasis / negative regulation of neurogenesis / peptide antigen assembly with MHC class II protein complex / positive regulation of receptor-mediated endocytosis / MHC class II protein complex / cellular response to nicotine / positive regulation of T cell mediated cytotoxicity / specific granule lumen / recycling endosome membrane / phagocytic vesicle membrane / positive regulation of cellular senescence / peptide antigen binding / negative regulation of epithelial cell proliferation / antigen processing and presentation of exogenous peptide antigen via MHC class II / Immunoregulatory interactions between a Lymphoid and a non-Lymphoid cell / Interferon gamma signaling / positive regulation of immune response / Modulation by Mtb of host immune system / sensory perception of smell / positive regulation of T cell activation / positive regulation of protein binding / tertiary granule lumen / DAP12 signaling / negative regulation of neuron projection development / MHC class II protein complex binding / late endosome membrane / iron ion transport / ER-Phagosome pathway / early endosome membrane / T cell differentiation in thymus / protein refolding / protein homotetramerization / intracellular iron ion homeostasis / amyloid fibril formation / learning or memory / Amyloid fiber formation / endoplasmic reticulum lumen / lysosomal membrane / external side of plasma membrane / Golgi membrane / focal adhesion / Neutrophil degranulation / SARS-CoV-2 activates/modulates innate and adaptive immune responses / structural molecule activity / Golgi apparatus / endoplasmic reticulum / 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: 3.975 Å | ||||||||||||||||||
![]() | Iadanza, M.G. / Ranson, N.A. | ||||||||||||||||||
Funding support | ![]() ![]()
| ||||||||||||||||||
![]() | ![]() Title: The structure of a β-microglobulin fibril suggests a molecular basis for its amyloid polymorphism. Authors: Matthew G Iadanza / Robert Silvers / Joshua Boardman / Hugh I Smith / Theodoros K Karamanos / Galia T Debelouchina / Yongchao Su / Robert G Griffin / Neil A Ranson / Sheena E Radford / ![]() ![]() Abstract: All amyloid fibrils contain a cross-β fold. How this structure differs in fibrils formed from proteins associated with different diseases remains unclear. Here, we combine cryo-EM and MAS-NMR to ...All amyloid fibrils contain a cross-β fold. How this structure differs in fibrils formed from proteins associated with different diseases remains unclear. Here, we combine cryo-EM and MAS-NMR to determine the structure of an amyloid fibril formed in vitro from β-microglobulin (βm), the culprit protein of dialysis-related amyloidosis. The fibril is composed of two identical protofilaments assembled from subunits that do not share βm's native tertiary fold, but are formed from similar β-strands. The fibrils share motifs with other amyloid fibrils, but also contain unique features including π-stacking interactions perpendicular to the fibril axis and an intramolecular disulfide that stabilises the subunit fold. We also describe a structural model for a second fibril morphology and show that it is built from the same subunit fold. The results provide insights into the mechanisms of fibril formation and the commonalities and differences within the amyloid fold in different protein sequences. | ||||||||||||||||||
History |
|
-
Structure visualization
Movie |
![]() |
---|---|
Structure viewer | Molecule: ![]() ![]() |
-
Downloads & links
-
Download
PDBx/mmCIF format | ![]() | 98.1 KB | Display | ![]() |
---|---|---|---|---|
PDB format | ![]() | 80.4 KB | Display | ![]() |
PDBx/mmJSON format | ![]() | Tree view | ![]() | |
Others | ![]() |
-Validation report
Summary document | ![]() | 664.9 KB | Display | ![]() |
---|---|---|---|---|
Full document | ![]() | 683 KB | Display | |
Data in XML | ![]() | 26.9 KB | Display | |
Data in CIF | ![]() | 38.9 KB | Display | |
Arichive directory | ![]() ![]() | HTTPS FTP |
-Related structure data
Related structure data | ![]() 0014MC ![]() 0021C M: map data used to model this data C: citing same article ( |
---|---|
Similar structure data | |
EM raw data | ![]() Data size: 294.3 Data #1: Aligned, dose-weighted micrographs [micrographs - single frame]) |
-
Links
-
Assembly
Deposited unit | ![]()
|
---|---|
1 |
|
-
Components
#1: Protein | Mass: 7635.446 Da / Num. of mol.: 8 Source method: isolated from a genetically manipulated source Source: (gene. exp.) ![]() ![]() ![]() |
---|
-Experimental details
-Experiment
Experiment | Method: ELECTRON MICROSCOPY |
---|---|
EM experiment | Aggregation state: FILAMENT / 3D reconstruction method: helical reconstruction |
-
Sample preparation
Component | Name: two protofilament beta-2-microglobulin amyloid fibril / Type: COMPLEX / Entity ID: all / Source: RECOMBINANT | ||||||||||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Molecular weight | Value: 53.3 kDa/nm / Experimental value: NO | ||||||||||||||||||||
Source (natural) | Organism: ![]() | ||||||||||||||||||||
Source (recombinant) | Organism: ![]() ![]() | ||||||||||||||||||||
Buffer solution | pH: 2.5 | ||||||||||||||||||||
Buffer component |
| ||||||||||||||||||||
Specimen | Conc.: 0.025 mg/ml / Embedding applied: NO / Shadowing applied: NO / Staining applied: NO / Vitrification applied: YES Details: Quiescent growth at 0.25 mg/ml for 5 weeks, diluted 10x with buffer | ||||||||||||||||||||
Specimen support | Grid material: COPPER / Grid mesh size: 400 divisions/in. / Grid type: Quantifoil R3.5/1 | ||||||||||||||||||||
Vitrification | Instrument: FEI VITROBOT MARK II / Cryogen name: ETHANE / Humidity: 80 % / Chamber temperature: 281.15 K |
-
Electron microscopy imaging
Experimental equipment | ![]() Model: Titan Krios / Image courtesy: FEI Company |
---|---|
Microscopy | Model: FEI TITAN KRIOS |
Electron gun | Electron source: ![]() |
Electron lens | Mode: BRIGHT FIELD / Nominal magnification: 130000 X / Nominal defocus max: 3.25 nm / Nominal defocus min: 1.75 nm / Cs: 2.7 mm / C2 aperture diameter: 100 µm / Alignment procedure: COMA FREE |
Specimen holder | Cryogen: NITROGEN / Specimen holder model: FEI TITAN KRIOS AUTOGRID HOLDER |
Image recording | Average exposure time: 10 sec. / Electron dose: 38.5 e/Å2 / Detector mode: COUNTING / Film or detector model: GATAN K2 SUMMIT (4k x 4k) / Num. of grids imaged: 1 / Num. of real images: 5549 |
Image scans | Movie frames/image: 40 / Used frames/image: 3-40 |
-
Processing
EM software |
| ||||||||||||||||||||||||||||||||||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
CTF correction | Type: PHASE FLIPPING AND AMPLITUDE CORRECTION | ||||||||||||||||||||||||||||||||||||||||||||
Helical symmerty | Angular rotation/subunit: -0.608 ° / Axial rise/subunit: 4.83 Å / Axial symmetry: C2 | ||||||||||||||||||||||||||||||||||||||||||||
Particle selection | Num. of particles selected: 99000 / Details: 300 x 300 pixel Overlapping segments 90% overlap | ||||||||||||||||||||||||||||||||||||||||||||
3D reconstruction | Resolution: 3.975 Å / Resolution method: FSC 0.143 CUT-OFF / Num. of particles: 11035 / Algorithm: FOURIER SPACE / Num. of class averages: 1 / Symmetry type: HELICAL | ||||||||||||||||||||||||||||||||||||||||||||
Atomic model building | Protocol: OTHER / Space: REAL | ||||||||||||||||||||||||||||||||||||||||||||
Refinement | Highest resolution: 3.9 Å |