+Open data
-Basic information
Entry | Database: PDB / ID: 8trm | |||||||||
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Title | Actin 1 from T. gondii in filaments bound to MgADP | |||||||||
Components | Actin | |||||||||
Keywords | STRUCTURAL PROTEIN / Actin / cytoskeleton / toxoplasmosis | |||||||||
Function / homology | Function and homology information Hydrolases; Acting on acid anhydrides; Acting on acid anhydrides to facilitate cellular and subcellular movement / cytoskeleton / hydrolase activity / ATP binding / cytoplasm Similarity search - Function | |||||||||
Biological species | Toxoplasma gondii (eukaryote) | |||||||||
Method | ELECTRON MICROSCOPY / helical reconstruction / cryo EM / Resolution: 2.5 Å | |||||||||
Authors | Hvorecny, K.L. / Sladewski, T.E. / Heaslip, A.T. / Kollman, J.M. | |||||||||
Funding support | United States, 2items
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Citation | Journal: Nat Commun / Year: 2024 Title: Toxoplasma gondii actin filaments are tuned for rapid disassembly and turnover. Authors: Kelli L Hvorecny / Thomas E Sladewski / Enrique M De La Cruz / Justin M Kollman / Aoife T Heaslip / Abstract: The cytoskeletal protein actin plays a critical role in the pathogenicity of the intracellular parasite, Toxoplasma gondii, mediating invasion and egress, cargo transport, and organelle inheritance. ...The cytoskeletal protein actin plays a critical role in the pathogenicity of the intracellular parasite, Toxoplasma gondii, mediating invasion and egress, cargo transport, and organelle inheritance. Advances in live cell imaging have revealed extensive filamentous actin networks in the Apicomplexan parasite, but there are conflicting data regarding the biochemical and biophysical properties of Toxoplasma actin. Here, we imaged the in vitro assembly of individual Toxoplasma actin filaments in real time, showing that native, unstabilized filaments grow tens of microns in length. Unlike skeletal muscle actin, Toxoplasma filaments intrinsically undergo rapid treadmilling due to a high critical concentration, fast monomer dissociation, and rapid nucleotide exchange. Cryo-EM structures of jasplakinolide-stabilized and native (i.e. unstabilized) filaments show an architecture like skeletal actin, with differences in assembly contacts in the D-loop that explain the dynamic nature of the filament, likely a conserved feature of Apicomplexan actin. This work demonstrates that evolutionary changes at assembly interfaces can tune the dynamic properties of actin filaments without disrupting their conserved structure. | |||||||||
History |
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-Structure visualization
Structure viewer | Molecule: MolmilJmol/JSmol |
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-Downloads & links
-Download
PDBx/mmCIF format | 8trm.cif.gz | 220.8 KB | Display | PDBx/mmCIF format |
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PDB format | pdb8trm.ent.gz | 177.7 KB | Display | PDB format |
PDBx/mmJSON format | 8trm.json.gz | Tree view | PDBx/mmJSON format | |
Others | Other downloads |
-Validation report
Summary document | 8trm_validation.pdf.gz | 1.2 MB | Display | wwPDB validaton report |
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Full document | 8trm_full_validation.pdf.gz | 1.2 MB | Display | |
Data in XML | 8trm_validation.xml.gz | 42.6 KB | Display | |
Data in CIF | 8trm_validation.cif.gz | 57.4 KB | Display | |
Arichive directory | https://data.pdbj.org/pub/pdb/validation_reports/tr/8trm ftp://data.pdbj.org/pub/pdb/validation_reports/tr/8trm | HTTPS FTP |
-Related structure data
Related structure data | 41583MC 8trnC M: map data used to model this data C: citing same article (ref.) |
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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: 41956.711 Da / Num. of mol.: 3 Source method: isolated from a genetically manipulated source Source: (gene. exp.) Toxoplasma gondii (eukaryote) / Gene: ACT1 / Plasmid: pFastBac / Cell line (production host): Sf9 / Production host: Spodoptera frugiperda (fall armyworm) References: UniProt: P53476, Hydrolases; Acting on acid anhydrides; Acting on acid anhydrides to facilitate cellular and subcellular movement #2: Chemical | #3: Chemical | #4: Water | ChemComp-HOH / | Has ligand of interest | Y | |
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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 |
-Sample preparation
Component | Name: Filament of Actin 1 from T. gondii with MgADP / Type: COMPLEX Details: Actin protomers from T. gondii assemble into a two-start helix Entity ID: #1 / Source: RECOMBINANT |
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Molecular weight | Experimental value: NO |
Source (natural) | Organism: Toxoplasma gondii (eukaryote) |
Source (recombinant) | Organism: Spodoptera frugiperda (fall armyworm) / Strain: Sf9 / Plasmid: pFastBac |
Buffer solution | pH: 7.6 |
Specimen | Embedding applied: NO / Shadowing applied: NO / Staining applied: NO / Vitrification applied: YES |
Specimen support | Grid material: COPPER / Grid mesh size: 200 divisions/in. / Grid type: C-flat-1.2/1.3 |
Vitrification | Instrument: HOMEMADE PLUNGER / Cryogen name: ETHANE |
-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: FIELD EMISSION GUN / Accelerating voltage: 300 kV / Illumination mode: FLOOD BEAM |
Electron lens | Mode: BRIGHT FIELD / Nominal magnification: 105000 X / Nominal defocus max: 1850 nm / Nominal defocus min: 700 nm |
Image recording | Average exposure time: 10 sec. / Electron dose: 60 e/Å2 / Detector mode: SUPER-RESOLUTION / Film or detector model: GATAN K3 BIOQUANTUM (6k x 4k) |
-Processing
EM software |
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CTF correction | Type: PHASE FLIPPING AND AMPLITUDE CORRECTION | ||||||||||||||||||||||||||||||||||||||||
Helical symmerty | Angular rotation/subunit: -167 ° / Axial rise/subunit: 28.1 Å / Axial symmetry: C1 | ||||||||||||||||||||||||||||||||||||||||
3D reconstruction | Resolution: 2.5 Å / Resolution method: FSC 0.5 CUT-OFF / Num. of particles: 2248567 / Symmetry type: HELICAL | ||||||||||||||||||||||||||||||||||||||||
Atomic model building | Protocol: FLEXIBLE FIT |