ジャーナル: Mol Cell Biol / 年: 2018 タイトル: Molecular Architecture of the Essential Yeast Histone Acetyltransferase Complex NuA4 Redefines Its Multimodularity. 著者: Dheva Setiaputra / Salar Ahmad / Udit Dalwadi / Anne-Lise Steunou / Shan Lu / James D Ross / Meng-Qiu Dong / Jacques Côté / Calvin K Yip / 要旨: Conserved from yeast to humans, the NuA4 histone acetyltransferase is a large multisubunit complex essential for cell viability through the regulation of gene expression, genome maintenance, ...Conserved from yeast to humans, the NuA4 histone acetyltransferase is a large multisubunit complex essential for cell viability through the regulation of gene expression, genome maintenance, metabolism, and cell fate during development and stress. How the different NuA4 subunits work in concert with one another to perform these diverse functions remains unclear, and addressing this central question requires a comprehensive understanding of NuA4's molecular architecture and subunit organization. We have determined the structure of fully assembled native yeast NuA4 by single-particle electron microscopy. Our data revealed that NuA4 adopts a trilobal overall architecture, with each of the three lobes constituted by one or two functional modules. By performing cross-linking coupled to mass spectrometry analysis and protein interaction studies, we further mapped novel intermolecular interfaces within NuA4. Finally, we combined these new data with other known structural information of NuA4 subunits and subassemblies to construct a multiscale model to illustrate how the different NuA4 subunits and modules are spatially arranged. This model shows that the multiple chromatin reader domains are clustered together around the catalytic core, suggesting that NuA4's multimodular architecture enables it to engage in multivalent interactions with its nucleosome substrate.
Complexes were purified from yeast via affinity purification for a FLAG-tagged subunit. Purified complexes were subjected to glycerol gradient ultracentrifugation, fractionated, and analyzed by negative-stain electron microscopy.
試料ホルダーモデル: SIDE ENTRY, EUCENTRIC / ホルダー冷却材: NITROGEN
実験機器
モデル: Tecnai Spirit / 画像提供: FEI Company
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画像解析
粒子像選択
選択した数: 26402 詳細: A subset of 200 particles were picked manually using the RELION software and used to generate reference-free 2D class averages. Representative class averages were used as templates for ...詳細: A subset of 200 particles were picked manually using the RELION software and used to generate reference-free 2D class averages. Representative class averages were used as templates for automatic picking using RELION.
CTF補正
ソフトウェア:
名称
詳細
CTFFIND (ver. 3)
CTFFIND3 was used to fit CTFs to raw micrographs using the SPIDER interface.
SPIDER (ver. 22.10)
SPIDER was used to phase flip images for CTF correction.
詳細: CTFs of raw images were determined using CTFFIND3 and the images were phase-flipped using the SPIDER image suite.
初期モデル
モデルのタイプ: RANDOM CONICAL TILT / Random conical tilt - Tilt angle: 60 degrees
タイプ: NOT APPLICABLE / ソフトウェア - 名称: EMAN (ver. 2.12)
最終 角度割当
タイプ: PROJECTION MATCHING Projection matching processing - Number reference projections: 3072 Projection matching processing - Angular sampling: 1.875 degrees ソフトウェア - 名称: RELION (ver. 2) ソフトウェア - 詳細: RCT model was used as starting model for 3D classification and refinement using untilted dataset.
最終 3次元分類
クラス数: 4 / 平均メンバー数/クラス: 5791 / ソフトウェア - 名称: RELION (ver. 2) ソフトウェア - 詳細: RCT model was used as starting model for 3D classification using untilted dataset.