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Open data
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Basic information
Entry | Database: PDB / ID: 6vau | |||||||||
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Title | Bare actin filament from a partially cofilin-decorated sample | |||||||||
![]() | Actin, alpha skeletal muscle | |||||||||
![]() | STRUCTURAL PROTEIN / Cytoskeleton | |||||||||
Function / homology | ![]() cytoskeletal motor activator activity / tropomyosin binding / mesenchyme migration / troponin I binding / myosin heavy chain binding / filamentous actin / actin filament bundle / skeletal muscle thin filament assembly / striated muscle thin filament / actin filament bundle assembly ...cytoskeletal motor activator activity / tropomyosin binding / mesenchyme migration / troponin I binding / myosin heavy chain binding / filamentous actin / actin filament bundle / skeletal muscle thin filament assembly / striated muscle thin filament / actin filament bundle assembly / skeletal muscle myofibril / actin monomer binding / skeletal muscle fiber development / stress fiber / titin binding / actin filament polymerization / filopodium / actin filament / Hydrolases; Acting on acid anhydrides; Acting on acid anhydrides to facilitate cellular and subcellular movement / calcium-dependent protein binding / lamellipodium / cell body / hydrolase activity / protein domain specific binding / calcium ion binding / positive regulation of gene expression / magnesium ion binding / ATP binding / identical protein binding / cytoplasm Similarity search - Function | |||||||||
Biological species | ![]() ![]() | |||||||||
Method | ELECTRON MICROSCOPY / helical reconstruction / cryo EM / Resolution: 3.5 Å | |||||||||
![]() | Huehn, A.R. / Bibeau, J.P. / Schramm, A.C. / Cao, W. / De La Cruz, E.M. / Sindelar, C.V. | |||||||||
Funding support | ![]()
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![]() | ![]() Title: Structures of cofilin-induced structural changes reveal local and asymmetric perturbations of actin filaments. Authors: Andrew R Huehn / Jeffrey P Bibeau / Anthony C Schramm / Wenxiang Cao / Enrique M De La Cruz / Charles V Sindelar / ![]() Abstract: Members of the cofilin/ADF family of proteins sever actin filaments, increasing the number of filament ends available for polymerization or depolymerization. Cofilin binds actin filaments with ...Members of the cofilin/ADF family of proteins sever actin filaments, increasing the number of filament ends available for polymerization or depolymerization. Cofilin binds actin filaments with positive cooperativity, forming clusters of contiguously bound cofilin along the filament lattice. Filament severing occurs preferentially at boundaries between bare and cofilin-decorated (cofilactin) segments and is biased at 1 side of a cluster. A molecular understanding of cooperative binding and filament severing has been impeded by a lack of structural data describing boundaries. Here, we apply methods for analyzing filament cryo-electron microscopy (cryo-EM) data at the single subunit level to directly investigate the structure of boundaries within partially decorated cofilactin filaments. Subnanometer resolution maps of isolated, bound cofilin molecules and an actin-cofilactin boundary indicate that cofilin-induced actin conformational changes are local and limited to subunits directly contacting bound cofilin. An isolated, bound cofilin compromises longitudinal filament contacts of 1 protofilament, consistent with a single cofilin having filament-severing activity. An individual, bound phosphomimetic (S3D) cofilin with weak severing activity adopts a unique binding mode that does not perturb actin structure. Cofilin clusters disrupt both protofilaments, consistent with a higher severing activity at boundaries compared to single cofilin. Comparison of these structures indicates that this disruption is substantially greater at pointed end sides of cofilactin clusters than at the barbed end. These structures, with the distribution of bound cofilin clusters, suggest that maximum binding cooperativity is achieved when 2 cofilins occupy adjacent sites. These results reveal the structural origins of cooperative cofilin binding and actin filament severing. | |||||||||
History |
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Structure visualization
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Structure viewer | Molecule: ![]() ![]() |
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PDBx/mmCIF format | ![]() | 317.6 KB | Display | ![]() |
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PDB format | ![]() | 263.3 KB | Display | ![]() |
PDBx/mmJSON format | ![]() | Tree view | ![]() | |
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-Validation report
Summary document | ![]() | 1.2 MB | Display | ![]() |
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Full document | ![]() | 1.2 MB | Display | |
Data in XML | ![]() | 62.8 KB | Display | |
Data in CIF | ![]() | 92 KB | Display | |
Arichive directory | ![]() ![]() | HTTPS FTP |
-Related structure data
Related structure data | ![]() 20719MC ![]() 6ubyC ![]() 6uc0C ![]() 6uc4C ![]() 6vaoC M: map data used to model this data C: citing same article ( |
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Similar structure data |
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Assembly
Deposited unit | ![]()
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Components
#1: Protein | Mass: 42096.953 Da / Num. of mol.: 5 / Source method: isolated from a natural source / Source: (natural) ![]() ![]() #2: Chemical | ChemComp-MG / #3: Chemical | ChemComp-ADP / Has ligand of interest | N | |
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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: Actin filament / Type: COMPLEX / Entity ID: #1 / Source: NATURAL |
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Molecular weight | Experimental value: NO |
Source (natural) | Organism: ![]() ![]() |
Buffer solution | pH: 6.6 |
Specimen | Embedding applied: NO / Shadowing applied: NO / Staining applied: NO / Vitrification applied: YES |
Specimen support | Grid material: COPPER / Grid type: Quantifoil R1.2/1.3 |
Vitrification | 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 |
Image recording | Electron dose: 50 e/Å2 / Film or detector model: GATAN K2 SUMMIT (4k x 4k) |
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Processing
CTF correction | Type: PHASE FLIPPING AND AMPLITUDE CORRECTION |
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Helical symmerty | Angular rotation/subunit: -166.63 ° / Axial rise/subunit: 27.42 Å / Axial symmetry: C1 |
Particle selection | Num. of particles selected: 1117338 Details: Both bare and cofilin-decorated segments were selected and initially refined together. |
3D reconstruction | Resolution: 3.5 Å / Resolution method: FSC 0.143 CUT-OFF / Num. of particles: 559067 / Symmetry type: HELICAL |