National Institutes of Health/National Institute of General Medical Sciences (NIH/NIGMS)
米国
Howard Hughes Medical Institute (HHMI)
米国
引用
ジャーナル: Nature / 年: 2022 タイトル: Structural basis of NPR1 in activating plant immunity. 著者: Shivesh Kumar / Raul Zavaliev / Qinglin Wu / Ye Zhou / Jie Cheng / Lucas Dillard / Jordan Powers / John Withers / Jinshi Zhao / Ziqiang Guan / Mario J Borgnia / Alberto Bartesaghi / Xinnian Dong / Pei Zhou / 要旨: NPR1 is a master regulator of the defence transcriptome induced by the plant immune signal salicylic acid. Despite the important role of NPR1 in plant immunity, understanding of its regulatory ...NPR1 is a master regulator of the defence transcriptome induced by the plant immune signal salicylic acid. Despite the important role of NPR1 in plant immunity, understanding of its regulatory mechanisms has been hindered by a lack of structural information. Here we report cryo-electron microscopy and crystal structures of Arabidopsis NPR1 and its complex with the transcription factor TGA3. Cryo-electron microscopy analysis reveals that NPR1 is a bird-shaped homodimer comprising a central Broad-complex, Tramtrack and Bric-à-brac (BTB) domain, a BTB and carboxyterminal Kelch helix bundle, four ankyrin repeats and a disordered salicylic-acid-binding domain. Crystal structure analysis reveals a unique zinc-finger motif in BTB for interacting with ankyrin repeats and mediating NPR1 oligomerization. We found that, after stimulation, salicylic-acid-induced folding and docking of the salicylic-acid-binding domain onto ankyrin repeats is required for the transcriptional cofactor activity of NPR1, providing a structural explanation for a direct role of salicylic acid in regulating NPR1-dependent gene expression. Moreover, our structure of the TGA3-NPR1-TGA3 complex, DNA-binding assay and genetic data show that dimeric NPR1 activates transcription by bridging two fatty-acid-bound TGA3 dimers to form an enhanceosome. The stepwise assembly of the NPR1-TGA complex suggests possible hetero-oligomeric complex formation with other transcription factors, revealing how NPR1 reprograms the defence transcriptome.
凍結剤: ETHANE / チャンバー内湿度: 85 % / チャンバー内温度: 277.15 K / 装置: LEICA EM GP 詳細: 3 ul of the sample was applied to the grid and incubated for 60 s in the chamber set at 277.15 K and 85% humidity. The grid was blotted for 2.4 s, followed by plunge-freezing in liquid ethane ...詳細: 3 ul of the sample was applied to the grid and incubated for 60 s in the chamber set at 277.15 K and 85% humidity. The grid was blotted for 2.4 s, followed by plunge-freezing in liquid ethane cooled by liquid nitrogen..
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電子顕微鏡法
顕微鏡
FEI TITAN KRIOS
撮影
フィルム・検出器のモデル: GATAN K3 (6k x 4k) / 平均電子線量: 60.0 e/Å2