View source for 9eeb


==Tubulin cofactors D,E,G bound to tubulin dimer==
<StructureSection load='9eeb' size='340' side='right'caption='[[9eeb]], [[Resolution|resolution]] 3.70&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[9eeb]] is a 6 chain structure with sequence from [https://en.wikipedia.org/wiki/Saccharomyces_cerevisiae Saccharomyces cerevisiae] and [https://en.wikipedia.org/wiki/Sus_scrofa Sus scrofa]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=9EEB OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=9EEB FirstGlance]. <br>
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">Electron Microscopy, [[Resolution|Resolution]] 3.7&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=GDP:GUANOSINE-5-DIPHOSPHATE'>GDP</scene>, <scene name='pdbligand=GTP:GUANOSINE-5-TRIPHOSPHATE'>GTP</scene></td></tr>
<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=9eeb FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=9eeb OCA], [https://pdbe.org/9eeb PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=9eeb RCSB], [https://www.ebi.ac.uk/pdbsum/9eeb PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=9eeb ProSAT]</span></td></tr>
</table>
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== Publication Abstract from PubMed ==
Microtubule polarity and dynamic polymerization arise from the self-association properties of the alphabeta-tubulin heterodimer. For decades, it has remained unclear how the tubulin cofactors TBCD, TBCE, TBCC, and the Arl2 GTPase mediate the biogenesis of alphabeta-tubulin from individual alpha- and beta-tubulins. Here, we use cryo-electron microscopy to determine structures of tubulin cofactors bound to alphabeta-tubulin. TBCD, TBCE, and Arl2 form a heterotrimeric cage-like assembly, we term TBC-DEG, around the alphabeta-tubulin heterodimer. The TBC-DEG-alphabeta-tubulin structures show that TBC-DEG wraps around beta-tubulin while TBCE extends along alpha-tubulin. The TBC-DEG/TBCC-alphabeta-tubulin structures reveal that TBCC forms multi-domain interactions with Arl2 and TBCD to engage the alphabeta-tubulin intradimer-interface, promoting TBCE rotation while TBCD holds beta-tubulin. TBCC engages the GTP-bound Arl2, multiple sites of TBCD, and the native alphabeta-tubulin intradimer interface near the alpha-tubulin N-site GTP. Together, these structures uncover transition states for alphabeta-tubulin biogenesis and degradation, suggesting a vise-like, GTP-hydrolysis-dependent mechanism in which TBCC binding to TBC-DEG modulates alphabeta-tubulin interfaces. Our studies provide structural evidence that tubulin cofactors act as enzymatic regulators that assemble the invariant alphabeta-tubulin architecture. By catalyzing alpha- and beta-tubulin biogenesis and degradation, the TBC-DEG and TBCC assemblies regulate the polymerization competency of alphabeta-tubulin for microtubule formation.

Cryo-EM structures of the tubulin cofactors reveal the molecular basis of alpha/beta-tubulin biogenesis.,Taheri A, Wang Z, Singal B, Guo F, Al-Bassam J Nat Commun. 2025 Dec 29;17(1):1405. doi: 10.1038/s41467-025-68142-0. PMID:41461644<ref>PMID:41461644</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
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<div class="pdbe-citations 9eeb" style="background-color:#fffaf0;"></div>
== References ==
<references/>
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</StructureSection>
[[Category: Large Structures]]
[[Category: Saccharomyces cerevisiae]]
[[Category: Sus scrofa]]
[[Category: Al-bassam J]]
[[Category: Taheri A]]