National Institutes of Health/National Institute of General Medical Sciences (NIH/NIGMS)
R01-GM099989
米国
National Institutes of Health/National Institute of General Medical Sciences (NIH/NIGMS)
U24GM129547
米国
引用
ジャーナル: Nat Commun / 年: 2022 タイトル: Visualization of conformational changes and membrane remodeling leading to genome delivery by viral class-II fusion machinery. 著者: Vidya Mangala Prasad / Jelle S Blijleven / Jolanda M Smit / Kelly K Lee / 要旨: Chikungunya virus (CHIKV) is a human pathogen that delivers its genome to the host cell cytoplasm through endocytic low pH-activated membrane fusion mediated by class-II fusion proteins. Though ...Chikungunya virus (CHIKV) is a human pathogen that delivers its genome to the host cell cytoplasm through endocytic low pH-activated membrane fusion mediated by class-II fusion proteins. Though structures of prefusion, icosahedral CHIKV are available, structural characterization of virion interaction with membranes has been limited. Here, we have used cryo-electron tomography to visualize CHIKV's complete membrane fusion pathway, identifying key intermediary glycoprotein conformations coupled to membrane remodeling events. Using sub-tomogram averaging, we elucidate features of the low pH-exposed virion, nucleocapsid and full-length E1-glycoprotein's post-fusion structure. Contrary to class-I fusion systems, CHIKV achieves membrane apposition by protrusion of extended E1-glycoprotein homotrimers into the target membrane. The fusion process also features a large hemifusion diaphragm that transitions to a wide pore for intact nucleocapsid delivery. Our analyses provide comprehensive ultrastructural insights into the class-II virus fusion system function and direct mechanistic characterization of the fundamental process of protein-mediated membrane fusion.
根拠: 電子顕微鏡法, Shape and size of density map matches that of known crystal structure of E1-ectodomain homotrimer
タイプ
名称
対称操作
数
identity operation
1_555
1
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要素
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タンパク質 , 1種, 3分子 ABC
#1: タンパク質
SpikeglycoproteinE1 / E1 envelope glycoprotein
分子量: 42690.125 Da / 分子数: 3 / 断片: SPIKE GLYCOPROTEIN E1 / 由来タイプ: 天然 詳細: The previously determined X-ray crystal structure PDB ID 1RER was rigidly docked into the sub-tomogram averaged map but no further refinement was performed 由来: (天然) Chikungunya virus strain S27-African prototype (ウイルス) 参照: UniProt: P03315
The previously determined X-ray crystal structure PDB ID 1RER was rigidly docked into the sub- ...The previously determined X-ray crystal structure PDB ID 1RER was rigidly docked into the sub-tomogram averaged map but no further refinement was performed