ジャーナル: Nature / 年: 2015 タイトル: Structure of the immature HIV-1 capsid in intact virus particles at 8.8 Å resolution. 著者: Florian K M Schur / Wim J H Hagen / Michaela Rumlová / Tomáš Ruml / Barbara Müller / Hans-Georg Kräusslich / John A G Briggs / 要旨: Human immunodeficiency virus type 1 (HIV-1) assembly proceeds in two stages. First, the 55 kilodalton viral Gag polyprotein assembles into a hexameric protein lattice at the plasma membrane of the ...Human immunodeficiency virus type 1 (HIV-1) assembly proceeds in two stages. First, the 55 kilodalton viral Gag polyprotein assembles into a hexameric protein lattice at the plasma membrane of the infected cell, inducing budding and release of an immature particle. Second, Gag is cleaved by the viral protease, leading to internal rearrangement of the virus into the mature, infectious form. Immature and mature HIV-1 particles are heterogeneous in size and morphology, preventing high-resolution analysis of their protein arrangement in situ by conventional structural biology methods. Here we apply cryo-electron tomography and sub-tomogram averaging methods to resolve the structure of the capsid lattice within intact immature HIV-1 particles at subnanometre resolution, allowing unambiguous positioning of all α-helices. The resulting model reveals tertiary and quaternary structural interactions that mediate HIV-1 assembly. Strikingly, these interactions differ from those predicted by the current model based on in vitro-assembled arrays of Gag-derived proteins from Mason-Pfizer monkey virus. To validate this difference, we solve the structure of the capsid lattice within intact immature Mason-Pfizer monkey virus particles. Comparison with the immature HIV-1 structure reveals that retroviral capsid proteins, while having conserved tertiary structures, adopt different quaternary arrangements during virus assembly. The approach demonstrated here should be applicable to determine structures of other proteins at subnanometre resolution within heterogeneous environments.
名称: intact Mason-Pfizer Monkey virus particles / タイプ: sample / ID: 1000 詳細: The virus contained an inactivating mutation in the protease (D26N) 集合状態: Homohexameric / Number unique components: 1
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超分子 #1: Mason-Pfizer monkey virus
超分子
名称: Mason-Pfizer monkey virus / タイプ: virus / ID: 1 / Name.synonym: M-PMV / NCBI-ID: 11855 / 生物種: Mason-Pfizer monkey virus / ウイルスタイプ: VIRION / ウイルス・単離状態: SPECIES / ウイルス・エンベロープ: Yes / ウイルス・中空状態: No / Syn species name: M-PMV
宿主
生物種: Cercopithecidae (オナガザル) / 別称: VERTEBRATES
Host system
組換細胞: HEK293T / 組換プラスミド: pSARM
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実験情報
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構造解析
手法
クライオ電子顕微鏡法
解析
サブトモグラム平均法
試料の集合状態
particle
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試料調製
緩衝液
詳細: PBS
グリッド
詳細: C-Flat 2/2-3C glow discharged
凍結
凍結剤: ETHANE / チャンバー内湿度: 100 % / 装置: FEI VITROBOT MARK II 手法: Degassed C-Flat 2/2-3C grids were glow discharged for 30 seconds at 20 mA. Virus solution was diluted in PBS containing 10nm colloidal gold. 2 ul of this mixture was applied to a grid. Blotting time: 2 seconds
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電子顕微鏡法
顕微鏡
FEI TITAN KRIOS
アライメント法
Legacy - 非点収差: Objective lens astigmatism was corrected at nominal working magnification
試料ホルダーモデル: FEI TITAN KRIOS AUTOGRID HOLDER Tilt series - Axis1 - Min angle: -45 ° / Tilt series - Axis1 - Max angle: 60 °
実験機器
モデル: Titan Krios / 画像提供: FEI Company
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画像解析
詳細
Subtomogram averaging calculations were performed using the AV3 and TOM packages. Subtomograms were extracted from the surface of the virus.
最終 再構成
想定した対称性 - 点群: C6 (6回回転対称) / アルゴリズム: OTHER / 解像度のタイプ: BY AUTHOR / 解像度: 9.7 Å / 解像度の算出法: OTHER / ソフトウェア - 名称: TOM, AV3 詳細: Reconstruction carried out using subtomogram averaging. Subtomogram averaging was performed using scripts from the TOM (Nickell et al, 2005) and AV3 (Foerster et al, 2005) packages. 使用したサブトモグラム数: 12920