ジャーナル: Nat Commun / 年: 2024 タイトル: Alphavirus nsP3 organizes into tubular scaffolds essential for infection and the cytoplasmic granule architecture. 著者: Vasiliya Kril / Michael Hons / Celine Amadori / Claire Zimberger / Laurine Couture / Yara Bouery / Julien Burlaud-Gaillard / Andrei Karpov / Denis Ptchelkine / Alexandra L Thienel / Beate M ...著者: Vasiliya Kril / Michael Hons / Celine Amadori / Claire Zimberger / Laurine Couture / Yara Bouery / Julien Burlaud-Gaillard / Andrei Karpov / Denis Ptchelkine / Alexandra L Thienel / Beate M Kümmerer / Ambroise Desfosses / Rhian Jones / Philippe Roingeard / Laurent Meertens / Ali Amara / Juan Reguera / 要旨: Alphaviruses, such as chikungunya virus (CHIKV), are mosquito-borne viruses that represent a significant threat to human health due to the current context of global warming. Efficient alphavirus ...Alphaviruses, such as chikungunya virus (CHIKV), are mosquito-borne viruses that represent a significant threat to human health due to the current context of global warming. Efficient alphavirus infection relies on the activity of the non-structural protein 3 (nsP3), a puzzling multifunctional molecule whose role in infection remains largely unknown. NsP3 is a component of the plasma membrane-bound viral RNA replication complex (vRC) essential for RNA amplification and is also found in large cytoplasmic aggregates of unknown function Here, we report the cryo-electron microscopy (cryo-EM) structure of the CHIKV nsP3 at 2.35 Å resolution. We show that nsP3 assembles into tubular structures made by a helical arrangement of its alphavirus unique domain (AUD). The nsP3 helical scaffolds are consistent with crown structures found on tomographic reconstructions of the mature viral RCs. In addition, nsP3 helices assemble into cytoplasmic granules organized in a network of tubular structures that contain viral genomic RNA and capsid as well as host factors required for productive infection. Structure-guided mutagenesis identified residues that prevent or disturb nsP3 assemblies, resulting in impaired viral replication or transcription. Altogether, our results reveal an unexpected nsP3-dependent molecular organization essential for different phases of alphavirus infection.
想定した対称性 - らせんパラメータ - Δz: 2.782 Å 想定した対称性 - らせんパラメータ - ΔΦ: -164.175 ° 想定した対称性 - らせんパラメータ - 軸対称性: C1 (非対称) 解像度のタイプ: BY AUTHOR / 解像度: 2.52 Å / 解像度の算出法: FSC 0.143 CUT-OFF / ソフトウェア - 名称: cryoSPARC 詳細: The assembly was calculated from the helical reconstruction of nsP3 from PDB 8PHZ subunit A. This was refined on a local refinement map at 2.35 A resolution 使用した粒子像数: 807973
初期モデル
モデルのタイプ: INSILICO MODEL In silico モデル: Alphafold2 (Colabfold) was used to have a model of the CHIKV AUD domain