+Open data
-Basic information
Entry | Database: PDB / ID: 8uz0 | ||||||||||||
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Title | Straight actin filament from Arp2/3 branch junction sample (ADP) | ||||||||||||
Components | Actin, alpha skeletal muscle | ||||||||||||
Keywords | CYTOSOLIC PROTEIN / actin / arp2/3 / cytoskeleton / branch | ||||||||||||
Function / homology | Function and homology information cytoskeletal motor activator activity / tropomyosin binding / myosin heavy chain binding / mesenchyme migration / troponin I binding / filamentous actin / actin filament bundle / skeletal muscle thin filament assembly / actin filament bundle assembly / striated muscle thin filament ...cytoskeletal motor activator activity / tropomyosin binding / myosin heavy chain binding / mesenchyme migration / troponin I binding / filamentous actin / actin filament bundle / skeletal muscle thin filament assembly / actin filament bundle assembly / striated muscle thin filament / skeletal muscle myofibril / actin monomer binding / stress fiber / skeletal muscle fiber development / 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 | Oryctolagus cuniculus (rabbit) | ||||||||||||
Method | ELECTRON MICROSCOPY / helical reconstruction / cryo EM / Resolution: 2.8 Å | ||||||||||||
Authors | Chavali, S.S. / Chou, S.Z. / Sindelar, C.V. | ||||||||||||
Funding support | United States, 3items
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Citation | Journal: Nat Commun / Year: 2024 Title: Cryo-EM structures reveal how phosphate release from Arp3 weakens actin filament branches formed by Arp2/3 complex. Authors: Sai Shashank Chavali / Steven Z Chou / Wenxiang Cao / Thomas D Pollard / Enrique M De La Cruz / Charles V Sindelar / Abstract: Arp2/3 complex nucleates branched actin filaments for cell and organelle movements. Here we report a 2.7 Å resolution cryo-EM structure of the mature branch junction formed by S. pombe Arp2/3 ...Arp2/3 complex nucleates branched actin filaments for cell and organelle movements. Here we report a 2.7 Å resolution cryo-EM structure of the mature branch junction formed by S. pombe Arp2/3 complex that provides details about interactions with both mother and daughter filaments. We determine a second structure at 3.2 Å resolution with the phosphate analog BeF bound with ADP to Arp3 and ATP bound to Arp2. In this ADP-BeF transition state the outer domain of Arp3 is rotated 2° toward the mother filament compared with the ADP state and makes slightly broader contacts with actin in both the mother and daughter filaments. Thus, dissociation of P from the ADP-P transition state reduces the interactions of Arp2/3 complex with the actin filaments and may contribute to the lower mechanical stability of mature branch junctions with ADP bound to the Arps. Our structures also reveal that the mother filament in contact with Arp2/3 complex is slightly bent and twisted, consistent with the preference of Arp2/3 complex binding curved actin filaments. The small degree of twisting constrains models of actin filament mechanics. | ||||||||||||
History |
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-Structure visualization
Structure viewer | Molecule: MolmilJmol/JSmol |
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-Downloads & links
-Download
PDBx/mmCIF format | 8uz0.cif.gz | 1.1 MB | Display | PDBx/mmCIF format |
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PDB format | pdb8uz0.ent.gz | 995.7 KB | Display | PDB format |
PDBx/mmJSON format | 8uz0.json.gz | Tree view | PDBx/mmJSON format | |
Others | Other downloads |
-Validation report
Summary document | 8uz0_validation.pdf.gz | 1.7 MB | Display | wwPDB validaton report |
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Full document | 8uz0_full_validation.pdf.gz | 1.7 MB | Display | |
Data in XML | 8uz0_validation.xml.gz | 92.3 KB | Display | |
Data in CIF | 8uz0_validation.cif.gz | 140.7 KB | Display | |
Arichive directory | https://data.pdbj.org/pub/pdb/validation_reports/uz/8uz0 ftp://data.pdbj.org/pub/pdb/validation_reports/uz/8uz0 | HTTPS FTP |
-Related structure data
Related structure data | 42829MC 8uxwC 8uxxC 8uz1C C: citing same article (ref.) M: map data used to model this data |
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Similar structure data | Similarity search - Function & homologyF&H Search |
-Links
-Assembly
Deposited unit |
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1 |
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-Components
#1: Protein | Mass: 41516.340 Da / Num. of mol.: 9 / Source method: isolated from a natural source / Source: (natural) Oryctolagus cuniculus (rabbit) References: UniProt: P68135, Hydrolases; Acting on acid anhydrides; Acting on acid anhydrides to facilitate cellular and subcellular movement #2: Chemical | ChemComp-ADP / #3: Chemical | ChemComp-MG / Has ligand of interest | Y | |
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-Experimental details
-Experiment
Experiment | Method: ELECTRON MICROSCOPY |
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EM experiment | Aggregation state: PARTICLE / 3D reconstruction method: helical reconstruction |
-Sample preparation
Component | Name: Actin / Type: ORGANELLE OR CELLULAR COMPONENT / Details: Actin filament / Entity ID: #1 / Source: NATURAL |
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Source (natural) | Organism: Gallus gallus (chicken) |
Buffer solution | pH: 7.5 |
Specimen | Embedding applied: NO / Shadowing applied: NO / Staining applied: NO / Vitrification applied: YES Details: Actin monomers with bound Ca2+ were converted to Mg2+-actin by equilibrating with 50 micromolar MgCl2 and 0.2 mM EGTA (pH 7.5) for 10 min on ice. Actin was polymerized in the presence of ...Details: Actin monomers with bound Ca2+ were converted to Mg2+-actin by equilibrating with 50 micromolar MgCl2 and 0.2 mM EGTA (pH 7.5) for 10 min on ice. Actin was polymerized in the presence of capping protein (CP) by sequentially mixing 8.75 micromolar Mg-ATP-actin monomers with 0.75 micromolar CP and equilibrated at room temperature for 1 h. In parallel, Arp2/3 complex (0.4 micromolar) in QB buffer was activated by mixing 0.85 micromolar GCN4-VCA and 50 micromolar ATP and incubated at 4 degrees for 1 h. The capped actin filaments sample was then gently mixed with an equal volume of activated Arp2/3 complex sample using cut pipette tips and equilibrated at 4 degrees for 5 min. Daughter filaments were formed and elongated in the presence of CP by adding 0.25 micromolar Mg-actin monomers, 50 micromolar ATP, and 40 nM CP and incubated for 5 min at room temperature. This step was subsequently repeated 4 more times, then aged for ~90 min before preparing grids for cryo-EM data collection. |
Vitrification | Instrument: FEI VITROBOT MARK IV / Cryogen name: ETHANE / Humidity: 100 % / Chamber temperature: 277 K Details: The samples were incubated on the grid for 50 s and the extra solution was blotted using two Vitrobot filter papers (0.55/20 mm, Grade 595, Ted Pella) for 4 s at 0 blot force. The grids were ...Details: The samples were incubated on the grid for 50 s and the extra solution was blotted using two Vitrobot filter papers (0.55/20 mm, Grade 595, Ted Pella) for 4 s at 0 blot force. The grids were plunged into liquid ethane at ~180 degrees C with a wait time of 0.5 s. |
-Electron microscopy imaging
Experimental equipment | Model: Titan Krios / Image courtesy: FEI Company |
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Microscopy | Model: FEI TITAN KRIOS Details: The vitrified grids were screened for sample homogeneity and ice thickness in a Glacios 200 kV transmission electron microscope equipped with Gatan K2 summit camera. Electron micrographs for ...Details: The vitrified grids were screened for sample homogeneity and ice thickness in a Glacios 200 kV transmission electron microscope equipped with Gatan K2 summit camera. Electron micrographs for image reconstructions were collected using Titan Krios equipped with X-cold field emission gun at 300 kV, Gatan image filter with slit width of 20 eV and a nanoprobe. |
Electron gun | Electron source: FIELD EMISSION GUN / Accelerating voltage: 300 kV / Illumination mode: FLOOD BEAM |
Electron lens | Mode: BRIGHT FIELD / Nominal magnification: 64000 X / Nominal defocus max: 2500 nm / Nominal defocus min: 1200 nm / Cs: 2.7 mm |
Specimen holder | Cryogen: NITROGEN / Specimen holder model: FEI TITAN KRIOS AUTOGRID HOLDER |
Image recording | Average exposure time: 3.3 sec. / Electron dose: 51.4 e/Å2 / Film or detector model: GATAN K3 (6k x 4k) / Num. of real images: 8519 Details: Each movie contains 41 frames with a frame time of 0.08 s. A dose rate of 28.4 counts/pixel/s and a physical pixel size of 1.346 Angstroms was used. |
EM imaging optics | Energyfilter name: GIF Quantum LS Details: Electron micrographs for image reconstructions were collected using Titan Krios equipped with X-cold field emission gun at 300 kV, Gatan image filter with slit width of 20 eV and a nanoprobe. Energyfilter slit width: 20 eV |
-Processing
EM software |
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CTF correction | Type: PHASE FLIPPING AND AMPLITUDE CORRECTION | ||||||||||||||||||||||||||||||||||||||||
Helical symmerty | Angular rotation/subunit: -166.76 ° / Axial rise/subunit: 27.42 Å / Axial symmetry: C1 | ||||||||||||||||||||||||||||||||||||||||
Particle selection | Num. of particles selected: 2320824 | ||||||||||||||||||||||||||||||||||||||||
3D reconstruction | Resolution: 2.8 Å / Resolution method: FSC 0.143 CUT-OFF / Num. of particles: 490230 Details: For the final 3D reconstruction, no helical symmetry was applied Symmetry type: HELICAL |