National Institutes of Health/National Institute of General Medical Sciences
R01-GM107013
米国
National Institutes of Health/National Institute Of Allergy and Infectious Diseases
R01-AI147890
米国
National Institutes of Health/National Institute of General Medical Sciences
P30-GM110758
米国
National Science Foundation (United States)
1659534
米国
National Institutes of Health/National Institute Of Allergy and Infectious Diseases
AI142263
米国
National Institutes of Health/National Institute Of Allergy and Infectious Diseases
P50AI150481
米国
Medical Research Council (United Kingdom)
MC_UP_1201/16
英国
European Research Council
ERC-2014-CoG 648432 - MEMBRANEFUSION
英国
引用
ジャーナル: PLoS Pathog / 年: 2020 タイトル: Structures of immature EIAV Gag lattices reveal a conserved role for IP6 in lentivirus assembly. 著者: Robert A Dick / Chaoyi Xu / Dustin R Morado / Vladyslav Kravchuk / Clifton L Ricana / Terri D Lyddon / Arianna M Broad / J Ryan Feathers / Marc C Johnson / Volker M Vogt / Juan R Perilla / ...著者: Robert A Dick / Chaoyi Xu / Dustin R Morado / Vladyslav Kravchuk / Clifton L Ricana / Terri D Lyddon / Arianna M Broad / J Ryan Feathers / Marc C Johnson / Volker M Vogt / Juan R Perilla / John A G Briggs / Florian K M Schur / 要旨: Retrovirus assembly is driven by the multidomain structural protein Gag. Interactions between the capsid domains (CA) of Gag result in Gag multimerization, leading to an immature virus particle that ...Retrovirus assembly is driven by the multidomain structural protein Gag. Interactions between the capsid domains (CA) of Gag result in Gag multimerization, leading to an immature virus particle that is formed by a protein lattice based on dimeric, trimeric, and hexameric protein contacts. Among retroviruses the inter- and intra-hexamer contacts differ, especially in the N-terminal sub-domain of CA (CANTD). For HIV-1 the cellular molecule inositol hexakisphosphate (IP6) interacts with and stabilizes the immature hexamer, and is required for production of infectious virus particles. We have used in vitro assembly, cryo-electron tomography and subtomogram averaging, atomistic molecular dynamics simulations and mutational analyses to study the HIV-related lentivirus equine infectious anemia virus (EIAV). In particular, we sought to understand the structural conservation of the immature lentivirus lattice and the role of IP6 in EIAV assembly. Similar to HIV-1, IP6 strongly promoted in vitro assembly of EIAV Gag proteins into virus-like particles (VLPs), which took three morphologically highly distinct forms: narrow tubes, wide tubes, and spheres. Structural characterization of these VLPs to sub-4Å resolution unexpectedly showed that all three morphologies are based on an immature lattice with preserved key structural components, highlighting the structural versatility of CA to form immature assemblies. A direct comparison between EIAV and HIV revealed that both lentiviruses maintain similar immature interfaces, which are established by both conserved and non-conserved residues. In both EIAV and HIV-1, IP6 regulates immature assembly via conserved lysine residues within the CACTD and SP. Lastly, we demonstrate that IP6 stimulates in vitro assembly of immature particles of several other retroviruses in the lentivirus genus, suggesting a conserved role for IP6 in lentiviral assembly.
凍結剤: ETHANE / チャンバー内湿度: 90 % / チャンバー内温度: 288 K / 装置: FEI VITROBOT MARK II 詳細: 1-2 seconds blot time, offset -3mm 10 nm colloidal gold was added prior to vitrification.
詳細
Virus-like-particles (spherical) of EIAV Gag deltaMAdeltap9 (referred to as Gag deltaMA) assembled at pH8.
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電子顕微鏡法
顕微鏡
FEI TITAN KRIOS
特殊光学系
エネルギーフィルター - 名称: GIF Quantum LS / エネルギーフィルター - スリット幅: 20 eV
詳細
nanoprobe
撮影
フィルム・検出器のモデル: GATAN K2 QUANTUM (4k x 4k) 検出モード: SUPER-RESOLUTION / デジタル化 - サイズ - 横: 3708 pixel / デジタル化 - サイズ - 縦: 3838 pixel / 撮影したグリッド数: 1 / 平均露光時間: 1.8 sec. / 平均電子線量: 3.4 e/Å2 詳細: Data was acquired using a dose-symmetric tilt acquisition scheme, as described in Hagen et al, 2017, J. Struct. Biol, 197(2):191-8
Tilt series were low-pass filtered according to their cumulative dose using exposure filters that were calculated using an exposure-dependent amplitude attenuation function and critical exposure constants (as published in Grant & Grigorieff, Elife, 2015). Tilt series were aligned and reconstructed in IMOD.
最終 再構成
使用したクラス数: 1 / 想定した対称性 - 点群: C6 (6回回転対称) / 解像度のタイプ: BY AUTHOR / 解像度: 3.9 Å / 解像度の算出法: FSC 0.143 CUT-OFF / ソフトウェア: (名称: AV3, TOM Toolbox) / 使用したサブトモグラム数: 65807
抽出
トモグラム数: 37 / 使用した粒子像数: 191612 / ソフトウェア - 名称: MATLAB ソフトウェア - 詳細: partially based on the TOM toolbox 詳細: Subtomogram extraction positions were defined in Amira using the electron microscopy toolbox by determing the radii and the center of the VLPs. Initially, positions were oversampled and ...詳細: Subtomogram extraction positions were defined in Amira using the electron microscopy toolbox by determing the radii and the center of the VLPs. Initially, positions were oversampled and subsequently cleaned during alignments using cross-correlation and distance thresholds.
CTF補正
ソフトウェア: (名称: CTFFIND (ver. 4), CTFPHASEFLIP, NOVACTF) 詳細: CTF-correction was initially performed using ctfphaseflip in IMOD and NovaCTF in the final steps
最終 角度割当
タイプ: PROJECTION MATCHING Projection matching processing - Number reference projections: 1 Projection matching processing - Merit function: CC / ソフトウェア: (名称: AV3, TOM Toolbox) 詳細: Subtomogram alignment was performed as described in the published manuscript.