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Open data
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Basic information
Entry | Database: PDB / ID: 7o7p | |||||||||||||||
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Title | (h-alpha2M)4 activated state | |||||||||||||||
![]() | Alpha-2-macroglobulin | |||||||||||||||
![]() | PROTEIN BINDING / alpha2-macroglobulin / proteinase / serum proteostasis / hydrolase inhibitor | |||||||||||||||
Function / homology | ![]() negative regulation of complement activation, lectin pathway / interleukin-1 binding / brain-derived neurotrophic factor binding / embryonic liver development / acute inflammatory response to antigenic stimulus / interleukin-8 binding / luteinization / tumor necrosis factor binding / HDL assembly / response to carbon dioxide ...negative regulation of complement activation, lectin pathway / interleukin-1 binding / brain-derived neurotrophic factor binding / embryonic liver development / acute inflammatory response to antigenic stimulus / interleukin-8 binding / luteinization / tumor necrosis factor binding / HDL assembly / response to carbon dioxide / nerve growth factor binding / endopeptidase inhibitor activity / growth factor binding / response to prostaglandin E / response to glucocorticoid / Intrinsic Pathway of Fibrin Clot Formation / Degradation of the extracellular matrix / response to nutrient / negative regulation of peptidase activity / platelet alpha granule lumen / acute-phase response / stem cell differentiation / serine-type endopeptidase inhibitor activity / calcium-dependent protein binding / Platelet degranulation / protease binding / collagen-containing extracellular matrix / blood microparticle / signaling receptor binding / enzyme binding / extracellular space / extracellular exosome / extracellular region / identical protein binding Similarity search - Function | |||||||||||||||
Biological species | ![]() | |||||||||||||||
Method | ELECTRON MICROSCOPY / single particle reconstruction / cryo EM / Resolution: 4.6 Å | |||||||||||||||
![]() | Luque, D. / Goulas, T. / Mata, C.P. / Mendes, S.R. / Gomis-Ruth, F.X. / Caston, J.R. | |||||||||||||||
Funding support | ![]()
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![]() | ![]() Title: Cryo-EM structures show the mechanistic basis of pan-peptidase inhibition by human α-macroglobulin. Authors: Daniel Luque / Theodoros Goulas / Carlos P Mata / Soraia R Mendes / F Xavier Gomis-Rüth / José R Castón / ![]() ![]() ![]() Abstract: Human α2-macroglobulin (hα2M) is a multidomain protein with a plethora of essential functions, including transport of signaling molecules and endopeptidase inhibition in innate immunity. Here, we ...Human α2-macroglobulin (hα2M) is a multidomain protein with a plethora of essential functions, including transport of signaling molecules and endopeptidase inhibition in innate immunity. Here, we dissected the molecular mechanism of the inhibitory function of the ∼720-kDa hα2M tetramer through eight cryo–electron microscopy (cryo-EM) structures of complexes from human plasma. In the native complex, the hα2M subunits are organized in two flexible modules in expanded conformation, which enclose a highly porous cavity in which the proteolytic activity of circulating plasma proteins is tested. Cleavage of bait regions exposed inside the cavity triggers rearrangement to a compact conformation, which closes openings and entraps the prey proteinase. After the expanded-to-compact transition, which occurs independently in the four subunits, the reactive thioester bond triggers covalent linking of the proteinase, and the receptor-binding domain is exposed on the tetramer surface for receptor-mediated clearance from circulation. These results depict the molecular mechanism of a unique suicidal inhibitory trap. | |||||||||||||||
History |
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Structure visualization
Structure viewer | Molecule: ![]() ![]() |
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Downloads & links
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Download
PDBx/mmCIF format | ![]() | 889.5 KB | Display | ![]() |
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PDB format | ![]() | 728 KB | Display | ![]() |
PDBx/mmJSON format | ![]() | Tree view | ![]() | |
Others | ![]() |
-Validation report
Summary document | ![]() | 1.4 MB | Display | ![]() |
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Full document | ![]() | 1.5 MB | Display | |
Data in XML | ![]() | 141.6 KB | Display | |
Data in CIF | ![]() | 209 KB | Display | |
Arichive directory | ![]() ![]() | HTTPS FTP |
-Related structure data
Related structure data | ![]() 12752MC ![]() 7o7lC ![]() 7o7mC ![]() 7o7nC ![]() 7o7oC ![]() 7o7qC ![]() 7o7rC ![]() 7o7sC M: map data used to model this data C: citing same article ( |
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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: 163465.062 Da / Num. of mol.: 4 / Source method: isolated from a natural source / Source: (natural) ![]() #2: Polysaccharide | 2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose Source method: isolated from a genetically manipulated source #3: Sugar | ChemComp-NAG / Has ligand of interest | N | Has protein modification | Y | |
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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 |
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Sample preparation
Component | Name: Human alpha-2-macroglobulin activated state / Type: COMPLEX / Entity ID: #1 / Source: NATURAL |
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Molecular weight | Value: 0.7 MDa / Experimental value: NO |
Source (natural) | Organism: ![]() |
Buffer solution | pH: 7.5 |
Specimen | Conc.: 0.1 mg/ml / Embedding applied: NO / Shadowing applied: NO / Staining applied: NO / Vitrification applied: YES |
Specimen support | Grid material: COPPER/RHODIUM / Grid mesh size: 300 divisions/in. / Grid type: Quantifoil R2/2 |
Vitrification | Instrument: LEICA EM CPC / Cryogen name: ETHANE |
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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: 47775 X / Nominal defocus max: 3250 nm / Nominal defocus min: 1000 nm |
Specimen holder | Cryogen: NITROGEN / Specimen holder model: FEI TITAN KRIOS AUTOGRID HOLDER |
Image recording | Electron dose: 39.6 e/Å2 / Detector mode: COUNTING / Film or detector model: GATAN K2 SUMMIT (4k x 4k) / Num. of real images: 12143 |
Image scans | Movie frames/image: 32 |
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Processing
EM software |
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CTF correction | Type: NONE | ||||||||||||||||||||||||||||||||||||||||
Particle selection | Num. of particles selected: 1625000 | ||||||||||||||||||||||||||||||||||||||||
Symmetry | Point symmetry: C2 (2 fold cyclic) | ||||||||||||||||||||||||||||||||||||||||
3D reconstruction | Resolution: 4.6 Å / Resolution method: FSC 0.143 CUT-OFF / Num. of particles: 118333 / Algorithm: FOURIER SPACE / Symmetry type: POINT | ||||||||||||||||||||||||||||||||||||||||
Atomic model building | Protocol: OTHER / Space: REAL |