Spanish Ministry of Science, Innovation, and Universities
PGC2018-098701-B-I00
スペイン
Spanish Ministry of Economy and Competitiveness
SEV-2016-0644
スペイン
Spanish Ministry of Science, Innovation, and Universities
RTI2018-095700-B-I00
スペイン
引用
ジャーナル: J Biol Chem / 年: 2020 タイトル: The cryo-EM structure of African swine fever virus unravels a unique architecture comprising two icosahedral protein capsids and two lipoprotein membranes. 著者: German Andrés / Diego Charro / Tania Matamoros / Rebecca S Dillard / Nicola G A Abrescia / 要旨: African swine fever virus (ASFV) is a complex nucleocytoplasmic large DNA virus (NCLDV) that causes a devastating swine disease currently present in many countries of Africa, Europe, and Asia. ...African swine fever virus (ASFV) is a complex nucleocytoplasmic large DNA virus (NCLDV) that causes a devastating swine disease currently present in many countries of Africa, Europe, and Asia. Despite intense research efforts, relevant gaps in the architecture of the infectious virus particle remain. Here, we used single-particle cryo-EM to analyze the three-dimensional structure of the mature ASFV particle. Our results show that the ASFV virion, with a radial diameter of ∼2,080 Å, encloses a genome-containing nucleoid surrounded by two distinct icosahedral protein capsids and two lipoprotein membranes. The outer capsid forms a hexagonal lattice (triangulation number = 277) composed of 8,280 copies of the double jelly-roll major capsid protein (MCP) p72, arranged in trimers displaying a pseudo-hexameric morphology, and of 60 copies of a penton protein at the vertices. The inner protein layer, organized as a = 19 capsid, confines the core shell, and it is composed of the mature products derived from the ASFV polyproteins pp220 and pp62. Also, an icosahedral membrane lies between the two protein layers, whereas a pleomorphic envelope wraps the outer capsid. This high-level organization confers to ASFV a unique architecture among the NCLDVs that likely reflects the complexity of its infection process and may help explain current challenges in controlling it.
凍結剤: ETHANE / チャンバー内湿度: 100 % / チャンバー内温度: 277 K / 装置: FEI VITROBOT MARK III
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電子顕微鏡法
顕微鏡
FEI TITAN KRIOS
詳細
Two datasets were acquired.
撮影
#0 - Image recording ID: 1 #0 - フィルム・検出器のモデル: FEI FALCON III (4k x 4k) #0 - 平均電子線量: 47.7 e/Å2 #0 - 詳細: Titan Krios equipped with a Cs-corrector and a Falcon 3EC direct electron detector #1 - Image recording ID: 2 #1 - フィルム・検出器のモデル: GATAN K2 SUMMIT (4k x 4k) #1 - 平均電子線量: 47.5 e/Å2 #1 - 詳細: Titan Krios equipped with a Gatan K2 Summit direct electron detector
電子線
加速電圧: 300 kV / 電子線源: FIELD EMISSION GUN
電子光学系
照射モード: FLOOD BEAM / 撮影モード: DARK FIELD
実験機器
モデル: Titan Krios / 画像提供: FEI Company
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画像解析
Image recording ID
2
粒子像選択
選択した数: 1267 詳細: 583 from Falcon 3EC dataset plus 684 from K2 dataset
CTF補正
ソフトウェア - 名称: CTFFIND
最終 再構成
使用したクラス数: 2 / 想定した対称性 - 点群: I (正20面体型対称) / アルゴリズム: FOURIER SPACE / 解像度のタイプ: BY AUTHOR / 解像度: 23.1 Å / 解像度の算出法: FSC 0.143 CUT-OFF / ソフトウェア - 名称: RELION / 使用した粒子像数: 1110
初期 角度割当
タイプ: MAXIMUM LIKELIHOOD / ソフトウェア - 名称: RELION
最終 角度割当
タイプ: MAXIMUM LIKELIHOOD / ソフトウェア - 名称: RELION
最終 3次元分類
クラス数: 2 / ソフトウェア - 名称: RELION 詳細: From the first data collection 583 ASFV particles were visually selected and extracted in RELION, and 3D classified in two classes (as a reference an initial symmetrized model was generated ...詳細: From the first data collection 583 ASFV particles were visually selected and extracted in RELION, and 3D classified in two classes (as a reference an initial symmetrized model was generated in RELION). The largest class with 450 particles was refined and a preliminary icosahedral model of the virion was produced; this model served as reference for the 3D classification of the second dataset (684 starting particles) which led to a largest class with 650 particles. Then both set of particles were interpolated to the same pixel size and merged for 3D reconstruction.