National Institutes of Health/National Institute of Neurological Disorders and Stroke (NIH/NINDS)
ZO1 NS003163
米国
引用
ジャーナル: Nat Chem Biol / 年: 2024 タイトル: Structural basis for α-tubulin-specific and modification state-dependent glutamylation. 著者: Kishore K Mahalingan / Danielle A Grotjahn / Yan Li / Gabriel C Lander / Elena A Zehr / Antonina Roll-Mecak / 要旨: Microtubules have spatiotemporally complex posttranslational modification patterns. Tubulin tyrosine ligase-like (TTLL) enzymes introduce the most prevalent modifications on α-tubulin and β-tubulin. ...Microtubules have spatiotemporally complex posttranslational modification patterns. Tubulin tyrosine ligase-like (TTLL) enzymes introduce the most prevalent modifications on α-tubulin and β-tubulin. How TTLLs specialize for specific substrate recognition and ultimately modification-pattern generation is largely unknown. TTLL6, a glutamylase implicated in ciliopathies, preferentially modifies tubulin α-tails in microtubules. Cryo-electron microscopy, kinetic analysis and single-molecule biochemistry reveal an unprecedented quadrivalent recognition that ensures simultaneous readout of microtubule geometry and posttranslational modification status. By binding to a β-tubulin subunit, TTLL6 modifies the α-tail of the longitudinally adjacent tubulin dimer. Spanning two tubulin dimers along and across protofilaments (PFs) ensures fidelity of recognition of both the α-tail and the microtubule. Moreover, TTLL6 reads out and is stimulated by glutamylation of the β-tail of the laterally adjacent tubulin dimer, mediating crosstalk between α-tail and β-tail. This positive feedback loop can generate localized microtubule glutamylation patterns. Our work uncovers general principles that generate tubulin chemical and topographic complexity.
超分子 #1: TTLL6 bound to unmodified human microtubules
超分子
名称: TTLL6 bound to unmodified human microtubules / タイプ: complex / ID: 1 / 親要素: 0 / 含まれる分子: #1-#3 詳細: Microtubules were decorated with TTLL6 on electron microscopy grids
凍結剤: ETHANE / チャンバー内湿度: 100 % / チャンバー内温度: 303 K / 装置: FEI VITROBOT MARK IV 詳細: The sample was blotted with Whatman #5 blotting paper on both sides of the grid for 3 s with a blot offset of -1 using a Vitrobot Mark IV (Thermo Fisher Scientific) with a chamber set to 30C ...詳細: The sample was blotted with Whatman #5 blotting paper on both sides of the grid for 3 s with a blot offset of -1 using a Vitrobot Mark IV (Thermo Fisher Scientific) with a chamber set to 30C at 100% humidity and subsequently plunged into liquid ethane..
選択した数: 59044 詳細: Due to highly heterogeneous TTLL6 decoration of microtubules microtubules were manually selected. 59044 overlapping segments with a box size of 568 pixels were extracted every 82 A
初期モデル
モデルのタイプ: OTHER 詳細: synthetic microtubule references were generated in UCSF Chimera
最終 再構成
使用したクラス数: 1 / 想定した対称性 - 点群: C1 (非対称) / アルゴリズム: FOURIER SPACE / 解像度のタイプ: BY AUTHOR / 解像度: 3.6 Å / 解像度の算出法: FSC 0.143 CUT-OFF / 使用した粒子像数: 392289