National Institutes of Health/Office of the Director
DP2EB020402
米国
National Institutes of Health/Office of the Director
S10OD021634
米国
引用
ジャーナル: Nat Struct Mol Biol / 年: 2019 タイトル: An allosteric network in spastin couples multiple activities required for microtubule severing. 著者: Colby R Sandate / Agnieszka Szyk / Elena A Zehr / Gabriel C Lander / Antonina Roll-Mecak / 要旨: The AAA+ ATPase spastin remodels microtubule arrays through severing and its mutation is the most common cause of hereditary spastic paraplegias (HSP). Polyglutamylation of the tubulin C-terminal ...The AAA+ ATPase spastin remodels microtubule arrays through severing and its mutation is the most common cause of hereditary spastic paraplegias (HSP). Polyglutamylation of the tubulin C-terminal tail recruits spastin to microtubules and modulates severing activity. Here, we present a ~3.2 Å resolution cryo-EM structure of the Drosophila melanogaster spastin hexamer with a polyglutamate peptide bound in its central pore. Two electropositive loops arranged in a double-helical staircase coordinate the substrate sidechains. The structure reveals how concurrent nucleotide and substrate binding organizes the conserved spastin pore loops into an ordered network that is allosterically coupled to oligomerization, and suggests how tubulin tail engagement activates spastin for microtubule disassembly. This allosteric coupling may apply generally in organizing AAA+ protein translocases into their active conformations. We show that this allosteric network is essential for severing and is a hotspot for HSP mutations.
モデル: Quantifoil, UltrAuFoil, R1.2/1.3 / 材質: GOLD / メッシュ: 300 / 前処理 - タイプ: PLASMA CLEANING / 前処理 - 時間: 7 sec. / 前処理 - 雰囲気: OTHER 詳細: Grids were plasma-cleaned using a Solarus plasma cleaner (Gatan, Inc.)
凍結
凍結剤: ETHANE / チャンバー内湿度: 90 % / チャンバー内温度: 277.15 K / 装置: HOMEMADE PLUNGER 詳細: Sample was blotted approximately 4 seconds using Whatman No. 1 filter paper before plunge-freezing..
Collected in counting mode, 48 frames movie-1, exposure time 12 s (250 ms frames), exposure rate of ~5.6 e- pixel-1 s-1, total exposure of ~52 e- angstrom-2 (1.08 e- angstrom-2 frame-1).
粒子像選択
選択した数: 2736865 / 詳細: Template-picked particles
初期モデル
モデルのタイプ: OTHER 詳細: An ab initio model generated from ~1.26 million template-picked particles cryoSPARC was used as a startup model.