+Open data
-Basic information
Entry | Database: EMDB / ID: EMD-3134 | |||||||||
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Title | Electron cryo-microscopy of an immune pore | |||||||||
Map data | Reconstruction of the membrane attack complex | |||||||||
Sample |
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Keywords | cryo-EM / single particles / membrane protein | |||||||||
Biological species | Homo sapiens (human) | |||||||||
Method | single particle reconstruction / cryo EM / Resolution: 8.5 Å | |||||||||
Authors | Serna M / Bubeck D | |||||||||
Citation | Journal: Nat Commun / Year: 2016 Title: Structural basis of complement membrane attack complex formation. Authors: Marina Serna / Joanna L Giles / B Paul Morgan / Doryen Bubeck / Abstract: In response to complement activation, the membrane attack complex (MAC) assembles from fluid-phase proteins to form pores in lipid bilayers. MAC directly lyses pathogens by a 'multi-hit' mechanism; ...In response to complement activation, the membrane attack complex (MAC) assembles from fluid-phase proteins to form pores in lipid bilayers. MAC directly lyses pathogens by a 'multi-hit' mechanism; however, sublytic MAC pores on host cells activate signalling pathways. Previous studies have described the structures of individual MAC components and subcomplexes; however, the molecular details of its assembly and mechanism of action remain unresolved. Here we report the electron cryo-microscopy structure of human MAC at subnanometre resolution. Structural analyses define the stoichiometry of the complete pore and identify a network of interaction interfaces that determine its assembly mechanism. MAC adopts a 'split-washer' configuration, in contrast to the predicted closed ring observed for perforin and cholesterol-dependent cytolysins. Assembly precursors partially penetrate the lipid bilayer, resulting in an irregular β-barrel pore. Our results demonstrate how differences in symmetric and asymmetric components of the MAC underpin a molecular basis for pore formation and suggest a mechanism of action that extends beyond membrane penetration. | |||||||||
History |
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-Structure visualization
Movie |
Movie viewer |
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Structure viewer | EM map: SurfViewMolmilJmol/JSmol |
Supplemental images |
-Downloads & links
-EMDB archive
Map data | emd_3134.map.gz | 3.5 MB | EMDB map data format | |
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Header (meta data) | emd-3134-v30.xml emd-3134.xml | 13.5 KB 13.5 KB | Display Display | EMDB header |
Images | EMD3134_image.tif | 506.3 KB | ||
Archive directory | http://ftp.pdbj.org/pub/emdb/structures/EMD-3134 ftp://ftp.pdbj.org/pub/emdb/structures/EMD-3134 | HTTPS FTP |
-Validation report
Summary document | emd_3134_validation.pdf.gz | 212.7 KB | Display | EMDB validaton report |
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Full document | emd_3134_full_validation.pdf.gz | 211.8 KB | Display | |
Data in XML | emd_3134_validation.xml.gz | 5.5 KB | Display | |
Arichive directory | https://ftp.pdbj.org/pub/emdb/validation_reports/EMD-3134 ftp://ftp.pdbj.org/pub/emdb/validation_reports/EMD-3134 | HTTPS FTP |
-Related structure data
-Links
EMDB pages | EMDB (EBI/PDBe) / EMDataResource |
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-Map
File | Download / File: emd_3134.map.gz / Format: CCP4 / Size: 34.5 MB / Type: IMAGE STORED AS FLOATING POINT NUMBER (4 BYTES) | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Annotation | Reconstruction of the membrane attack complex | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Projections & slices | Image control
Images are generated by Spider. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Voxel size | X=Y=Z: 2.8 Å | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Density |
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Symmetry | Space group: 1 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Details | EMDB XML:
CCP4 map header:
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-Supplemental data
-Sample components
-Entire : Membrane attack complex
Entire | Name: Membrane attack complex |
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Components |
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-Supramolecule #1000: Membrane attack complex
Supramolecule | Name: Membrane attack complex / type: sample / ID: 1000 Details: Protein complex was assembled on liposomes and detergent solubilized Number unique components: 7 |
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Molecular weight | Theoretical: 1.8 MDa |
-Macromolecule #1: C5
Macromolecule | Name: C5 / type: protein_or_peptide / ID: 1 / Number of copies: 1 / Oligomeric state: monomer / Recombinant expression: No |
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Source (natural) | Organism: Homo sapiens (human) / synonym: Human / Tissue: Plasma |
Molecular weight | Theoretical: 190 KDa |
-Macromolecule #2: C6
Macromolecule | Name: C6 / type: protein_or_peptide / ID: 2 / Number of copies: 1 / Oligomeric state: monomer / Recombinant expression: No |
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Source (natural) | Organism: Homo sapiens (human) / synonym: Human / Tissue: Plasma |
Molecular weight | Theoretical: 120 KDa |
-Macromolecule #3: C7
Macromolecule | Name: C7 / type: protein_or_peptide / ID: 3 / Number of copies: 1 / Oligomeric state: monomer / Recombinant expression: No |
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Source (natural) | Organism: Homo sapiens (human) / synonym: Human / Tissue: Plasma |
Molecular weight | Theoretical: 110 KDa |
-Macromolecule #4: C8 alpha
Macromolecule | Name: C8 alpha / type: protein_or_peptide / ID: 4 / Number of copies: 1 / Oligomeric state: monomer / Recombinant expression: No |
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Source (natural) | Organism: Homo sapiens (human) / synonym: Human / Tissue: Plasma |
Molecular weight | Theoretical: 152 KDa |
-Macromolecule #5: C8 beta
Macromolecule | Name: C8 beta / type: protein_or_peptide / ID: 5 / Number of copies: 1 / Oligomeric state: monomer / Recombinant expression: No |
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Source (natural) | Organism: Homo sapiens (human) / synonym: Human / Tissue: Plasma |
Molecular weight | Theoretical: 152 KDa |
-Macromolecule #6: C8 gamma
Macromolecule | Name: C8 gamma / type: protein_or_peptide / ID: 6 / Number of copies: 1 / Oligomeric state: monomer / Recombinant expression: No |
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Source (natural) | Organism: Homo sapiens (human) / synonym: Human / Tissue: Plasma |
Molecular weight | Theoretical: 152 KDa |
-Macromolecule #7: C9
Macromolecule | Name: C9 / type: protein_or_peptide / ID: 7 / Number of copies: 18 / Oligomeric state: eighteen-mer / Recombinant expression: No |
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Source (natural) | Organism: Homo sapiens (human) / synonym: Human / Tissue: Plasma |
Molecular weight | Theoretical: 69 KDa |
-Experimental details
-Structure determination
Method | cryo EM |
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Processing | single particle reconstruction |
Aggregation state | particle |
-Sample preparation
Buffer | pH: 7.4 / Details: 20 mM HEPES-NaOH, 150 mM NaCl |
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Grid | Details: 300 mesh quantifoil R1.2/1.3 grids with thin carbon support |
Vitrification | Cryogen name: ETHANE / Chamber humidity: 90 % / Instrument: FEI VITROBOT MARK III |
-Electron microscopy
Microscope | FEI TITAN KRIOS |
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Date | Jul 2, 2015 |
Image recording | Category: CCD / Film or detector model: FEI FALCON II (4k x 4k) / Digitization - Sampling interval: 14.0 µm / Number real images: 622 / Average electron dose: 45 e/Å2 |
Electron beam | Acceleration voltage: 300 kV / Electron source: FIELD EMISSION GUN |
Electron optics | Illumination mode: FLOOD BEAM / Imaging mode: BRIGHT FIELD / Cs: 2.00 mm / Nominal defocus max: 4.0 µm / Nominal defocus min: 2.0 µm / Nominal magnification: 59000 |
Sample stage | Specimen holder model: FEI TITAN KRIOS AUTOGRID HOLDER |
Experimental equipment | Model: Titan Krios / Image courtesy: FEI Company |
-Image processing
Details | Particles were manually selected. |
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CTF correction | Details: CTFFIND3, phase flip on each particle |
Final reconstruction | Applied symmetry - Point group: C1 (asymmetric) / Algorithm: OTHER / Resolution.type: BY AUTHOR / Resolution: 8.5 Å / Resolution method: OTHER / Software - Name: RELION, EMAN2 / Number images used: 41981 |
-Atomic model buiding 1
Initial model | PDB ID: |
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Software | Name: Chimera |
Refinement | Space: REAL / Protocol: RIGID BODY FIT |
-Atomic model buiding 2
Initial model | PDB ID: |
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Software | Name: Chimera |
Refinement | Space: REAL / Protocol: RIGID BODY FIT |