9F6T

cryoEM structure of Asgard tubulin heterodimer AtubA/B with GTP

9F6T の概要

• エントリーDOI: 10.2210/pdb9f6t/pdb
• EMDBエントリー: 50239
• 分子名称: Asgard tubulin A (AtubA) from Candidatus Lokiarchaeum ossiferum, Asgard tubulin B (AtubB) from Candidatus Lokiarchaeum ossiferum, GUANOSINE-5'-TRIPHOSPHATE (3 entities in total)
• 機能のキーワード: cryoem, tubulin, asgard archaea, microtubule, cytosolic protein
• 由来する生物種: Candidatus Lokiarchaeum ossiferum; 詳細
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 93970.17

構造登録者

Wollweber, F.,Xu, J.,Ponce-Toled, R.I.,Rodrigues-Oliveira, T.,Malit, J.J.L.,Kokhanovska, A.,Schleper, C.,Pilhofer, M. (登録日: 2024-05-02, 公開日: 2025-04-02, 最終更新日: 2025-05-14)

主引用文献

Wollweber, F.,Xu, J.,Ponce-Toledo, R.I.,Marxer, F.,Rodrigues-Oliveira, T.,Possnecker, A.,Luo, Z.H.,Malit, J.J.L.,Kokhanovska, A.,Wieczorek, M.,Schleper, C.,Pilhofer, M.
Microtubules in Asgard archaea.
Cell, 188:2451-, 2025

PubMed Abstract: Microtubules are a hallmark of eukaryotes. Archaeal and bacterial homologs of tubulins typically form homopolymers and non-tubular superstructures. The origin of heterodimeric tubulins assembling into microtubules remains unclear. Here, we report the discovery of microtubule-forming tubulins in Asgard archaea, the closest known relatives of eukaryotes. These Asgard tubulins (AtubA/B) are closely related to eukaryotic α/β-tubulins and the enigmatic bacterial tubulins BtubA/B. Proteomics of Candidatus Lokiarchaeum ossiferum showed that AtubA/B were highly expressed. Cryoelectron microscopy structures demonstrate that AtubA/B form eukaryote-like heterodimers, which assembled into 5-protofilament bona fide microtubules in vitro. The additional paralog AtubB2 lacks a nucleotide-binding site and competitively displaced AtubB. These AtubA/B2 heterodimers polymerized into 7-protofilament non-canonical microtubules. In a sub-population of Ca. Lokiarchaeum ossiferum cells, cryo-tomography revealed tubular structures, while expansion microscopy identified AtubA/B cytoskeletal assemblies. Our findings suggest a pre-eukaryotic origin of microtubules and provide a framework for understanding the fundamental principles of microtubule assembly.

PubMed: 40120574
DOI: 10.1016/j.cell.2025.02.027

実験手法

ELECTRON MICROSCOPY (3.5 Å)