ジャーナル: Mol Microbiol / 年: 2020 タイトル: Bacteriophage MS2 displays unreported capsid variability assembling T = 4 and mixed capsids. 著者: Natàlia de Martín Garrido / Michael A Crone / Kailash Ramlaul / Paul A Simpson / Paul S Freemont / Christopher H S Aylett / 要旨: Bacteriophage MS2 is a positive-sense, single-stranded RNA virus encapsulated in an asymmetric T = 3 pseudo-icosahedral capsid. It infects Escherichia coli through the F-pilus, in which it binds ...Bacteriophage MS2 is a positive-sense, single-stranded RNA virus encapsulated in an asymmetric T = 3 pseudo-icosahedral capsid. It infects Escherichia coli through the F-pilus, in which it binds through a maturation protein incorporated into its capsid. Cryogenic electron microscopy has previously shown that its genome is highly ordered within virions, and that it regulates the assembly process of the capsid. In this study, we have assembled recombinant MS2 capsids with non-genomic RNA containing the capsid incorporation sequence, and investigated the structures formed, revealing that T = 3, T = 4 and mixed capsids between these two triangulation numbers are generated, and resolving structures of T = 3 and T = 4 capsids to 4 Å and 6 Å respectively. We conclude that the basic MS2 capsid can form a mix of T = 3 and T = 4 structures, supporting a role for the ordered genome in favouring the formation of functional T = 3 virions.
凍結剤: ETHANE / チャンバー内湿度: 95 % / チャンバー内温度: 278 K / 装置: FEI VITROBOT MARK IV
-
電子顕微鏡法
顕微鏡
FEI TECNAI F20
撮影
フィルム・検出器のモデル: FEI FALCON I (4k x 4k) デジタル化 - サイズ - 横: 4096 pixel / デジタル化 - サイズ - 縦: 4096 pixel / 撮影したグリッド数: 4 / 実像数: 2129 / 平均露光時間: 4.0 sec. / 平均電子線量: 80.0 e/Å2 詳細: Frames were obtained with a beam-splitter Images were recorded at both 100kx and 150kx and resampled in Fourier space to 100kx for refinement
使用したクラス数: 1 / 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: 6.0 Å / 解像度の算出法: FSC 0.143 CUT-OFF / ソフトウェア - 名称: RELION / ソフトウェア - 詳細: Version 2.1 詳細: Resolution within a tight mask was 6.16 by FSC 0.143 cut-off while unmasked resolution was 7. 使用した粒子像数: 3499