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Open data
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Basic information
| Entry | Database: PDB / ID: 9na9 | ||||||
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| Title | Augmin1345-Extended-Tripod | ||||||
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Keywords | PLANT PROTEIN / Augmin1345-extended-Tripod | ||||||
| Function / homology | Function and homology informationphragmoplast microtubule organization / HAUS complex / microtubule minus-end binding / phragmoplast / spindle assembly / bioluminescence / generation of precursor metabolites and energy / spindle microtubule / spindle / microtubule ...phragmoplast microtubule organization / HAUS complex / microtubule minus-end binding / phragmoplast / spindle assembly / bioluminescence / generation of precursor metabolites and energy / spindle microtubule / spindle / microtubule / cell division / nucleus Similarity search - Function | ||||||
| Biological species | ![]() ![]() | ||||||
| Method | ELECTRON MICROSCOPY / single particle reconstruction / cryo EM / Resolution: 5.9 Å | ||||||
Authors | Ashaduzzaman, M. / Al-Bassam, J. / Taheri, A. | ||||||
| Funding support | United States, 1items
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Citation | Journal: bioRxiv / Year: 2025Title: Cryo-EM structures of the Plant Augmin reveal its intertwined coiled-coil assembly, antiparallel dimerization and NEDD1 binding mechanisms. Authors: Md Ashaduzzaman / Aryan Taheri / Yuh-Ru Julie Lee / Yuqi Tang / Fei Guo / Stephen D Fried / Bo Liu / Jawdat Al-Bassam / ![]() Abstract: Microtubule (MT) branch nucleation is fundamental for building parallel MT networks in eukaryotic cells. In plants and metazoans, MT branch nucleation requires Augmin and NEDD1 proteins which bind ...Microtubule (MT) branch nucleation is fundamental for building parallel MT networks in eukaryotic cells. In plants and metazoans, MT branch nucleation requires Augmin and NEDD1 proteins which bind along MTs and then recruit and activate the gamma-tubulin ring complex (γ-TuRC). Augmin is a fork-shaped assembly composed of eight coiled-coil subunits, while NEDD1 is a WD40 β-propellor protein that bridges across MTs, Augmin, and γ-TuRC during MT branch nucleation. Here, we reconstitute hetero-tetrameric and hetero-octameric Arabidopsis thaliana Augmin assemblies, resolve their subunit interactions using crosslinking mass spectrometry and determine 3.7 to 7.3-Å cryo-EM structures for the V-junction and extended regions of Augmin. These structures allowed us to generate a complete de novo plant Augmin model that reveals the long-range multi coiled-coil interfaces that stabilize its 40-nm hetero-octameric fork-shaped organization. We discovered the dual calponin homology (CH) domain forming its MT binding site at the end of its V-junction undertake open and closed conformations. We determined a 12-Å dimeric Augmin cryo-EM structure revealing Augmin undergoes anti-parallel dimerization through two conserved surfaces along Augmin's extended region. We reconstituted the NEDD1 WD40 β-propellor with Augmin revealing it directly binds on top its V-junction and enhances Augmin dimerization. Our studies suggest that cooperativity between the Augmin dual CH domains and NEDD1 WD40 binding site may regulate Augmin V-junction dual binding to MT lattices. This unique V-shaped dual binding and organization anchors Augmins along MTs generating a platform to recruit γ-TuRC and activate branched MT nucleation. | ||||||
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Structure visualization
| Structure viewer | Molecule: Molmil Jmol/JSmol |
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Downloads & links
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Download
| PDBx/mmCIF format | 9na9.cif.gz | 147.8 KB | Display | PDBx/mmCIF format |
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| PDB format | pdb9na9.ent.gz | 89.5 KB | Display | PDB format |
| PDBx/mmJSON format | 9na9.json.gz | Tree view | PDBx/mmJSON format | |
| Others | Other downloads |
-Validation report
| Summary document | 9na9_validation.pdf.gz | 1.1 MB | Display | wwPDB validaton report |
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| Full document | 9na9_full_validation.pdf.gz | 1.1 MB | Display | |
| Data in XML | 9na9_validation.xml.gz | 38.2 KB | Display | |
| Data in CIF | 9na9_validation.cif.gz | 54 KB | Display | |
| Arichive directory | https://data.pdbj.org/pub/pdb/validation_reports/na/9na9 ftp://data.pdbj.org/pub/pdb/validation_reports/na/9na9 | HTTPS FTP |
-Related structure data
| Related structure data | ![]() 49183MC ![]() 9na8C ![]() 9nbaC ![]() 9nbbC ![]() 9nbdC ![]() 9nbiC M: map data used to model this data C: citing same article ( |
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| Similar structure data | Similarity search - Function & homology F&H Search |
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Links
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Assembly
| Deposited unit | ![]()
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Components
| #1: Protein | Mass: 33537.996 Da / Num. of mol.: 1 Source method: isolated from a genetically manipulated source Source: (gene. exp.) ![]() ![]() |
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| #2: Protein | Mass: 47825.855 Da / Num. of mol.: 1 Source method: isolated from a genetically manipulated source Source: (gene. exp.) ![]() ![]() |
| #3: Protein | Mass: 116629.992 Da / Num. of mol.: 1 Source method: isolated from a genetically manipulated source Source: (gene. exp.) ![]() ![]() Gene: AUG5, At5g38880, K15E6.9, GFP / Production host: ![]() |
| #4: Protein | Mass: 69809.453 Da / Num. of mol.: 1 Source method: isolated from a genetically manipulated source Source: (gene. exp.) ![]() ![]() |
| Has protein modification | Y |
-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: Augmin tetramer complex tripod / Type: COMPLEX / Entity ID: all / Source: RECOMBINANT |
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| Molecular weight | Value: 0.31 MDa / Experimental value: YES |
| Source (natural) | Organism: ![]() |
| Source (recombinant) | Organism: ![]() |
| Buffer solution | pH: 7.5 |
| Buffer component | Conc.: 50 mM / Name: HEPES |
| Specimen | Embedding applied: NO / Shadowing applied: NO / Staining applied: NO / Vitrification applied: YES |
| Specimen support | Grid material: COPPER / Grid mesh size: 300 divisions/in. / Grid type: Quantifoil R1.2/1.3 |
| Vitrification | Instrument: LEICA EM GP / Cryogen name: ETHANE / Humidity: 95 % / Chamber temperature: 293 K |
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Electron microscopy imaging
| Microscopy | Model: TFS GLACIOS |
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| Electron gun | Electron source: FIELD EMISSION GUN / Accelerating voltage: 200 kV / Illumination mode: FLOOD BEAM |
| Electron lens | Mode: BRIGHT FIELD / Nominal defocus max: 1800 nm / Nominal defocus min: 600 nm |
| Image recording | Electron dose: 60 e/Å2 / Film or detector model: GATAN K3 (6k x 4k) |
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Processing
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| CTF correction | Type: NONE | ||||||||||||||||||||||||||||||||
| 3D reconstruction | Resolution: 5.9 Å / Resolution method: FSC 0.143 CUT-OFF / Num. of particles: 72002 / Num. of class averages: 1 / Symmetry type: POINT | ||||||||||||||||||||||||||||||||
| Refinement | Highest resolution: 5.9 Å / Cross valid method: NONE Stereochemistry target values: REAL-SPACE (WEIGHTED MAP SUM AT ATOM CENTERS) | ||||||||||||||||||||||||||||||||
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