9PZMSummary for 9PZM
| Entry DOI | 10.2210/pdb9pzm/pdb |
| EMDB information | 72072 |
| Descriptor | AUGMIN subunit 2, AUGMIN subunit 3, AUGMIN subunit 5, ... (7 entities in total) |
| Functional Keywords | microtubule nucleator, plant protein |
| Biological source | Arabidopsis thaliana (thale cress) More |
| Total number of polymer chains | 7 |
| Total formula weight | 299662.84 |
| Authors | Ashaduzzaman, M.,Al-Bassam, J. (deposition date: 2025-08-11, release date: 2026-01-07, Last modification date: 2026-07-22) |
| Primary citation | Ashaduzzaman, M.,Taheri, A.,Lee, Y.J.,Tang, Y.,Mittal, S.,Guo, F.,Morcos, F.,Fried, S.D.,Liu, B.,Al-Bassam, J. Cryo-EM structures of plant Augmin reveal coiled-coil assembly, antiparallel dimerization, and NEDD1 binding. Nat Commun, 16:11440-11440, 2025 Cited by PubMed Abstract: Microtubule (MT) branch nucleation requires Augmin and NEDD1 proteins, which recruit and activate the gamma-tubulin ring complex (γ-TuRC). Augmin is a fork-shaped assembly of eight coiled-coil subunits, while NEDD1 is a β-propeller protein bridging MTs, Augmin, and γ-TuRC. We reconstitute Arabidopsis thaliana Augmin assemblies and determine 3.7-7.3-Å cryo-EM structures of its V-junction and extended regions using crosslinking mass spectrometry. These structures reveal a complete plant Augmin model showing multi-coiled-coil interfaces stabilizing its 40-nm hetero-octameric fork architecture. The dual calponin homology (CH) domains at the V-junction terminus adopt open and closed conformations for MT binding. A 12-Å cryo-EM structure shows Augmin undergoes anti-parallel dimerization through conserved surfaces on its extended region. We determine the NEDD1 β-propeller structure with Augmin, revealing direct binding inside the V-junction that enhances dimerization. Direct coupling and evolutionary analyses identify co-varying residue pairs validating the eight-subunit model and NEDD1 interface. Cooperativity between dual CH domains and NEDD1 binding may regulate V-junction binding to MT lattices. This V-shaped dual binding anchors Augmin along MTs, creating platforms for γ-TuRC recruitment and branched MT nucleation. PubMed: 41387433DOI: 10.1038/s41467-025-66332-4 PDB entries with the same primary citation |
| Experimental method | ELECTRON MICROSCOPY (8 Å) |
Structure validation
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