8D87

Fitted crystal structure of the homotrimer of fusion glycoprotein E1 from SFV into subtomogram averaged CHIKV E1 glycoprotein density

Summary for 8D87

• Entry DOI: 10.2210/pdb8d87/pdb
• EMDB information: 27248
• Descriptor: Spike glycoprotein E1, 2-acetamido-2-deoxy-beta-D-glucopyranose-(1-2)-beta-D-mannopyranose-(1-3)-beta-D-mannopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-[beta-L-fucopyranose-(1-6)]2-acetamido-2-deoxy-beta-D-glucopyranose, 2-acetamido-2-deoxy-beta-D-glucopyranose-(1-2)-alpha-D-mannopyranose-(1-3)-[alpha-D-mannopyranose-(1-6)]beta-D-mannopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-[alpha-L-fucopyranose-(1-6)]2-acetamido-2-deoxy-alpha-D-glucopyranose, ... (8 entities in total)
• Functional Keywords: envelope glycoprotein, membrane fusion, virus, viral protein
• Biological source: Chikungunya virus strain S27-African prototype
• Total number of polymer chains: 3
• Total formula weight: 131847.35

Authors

Mangala Prasad, V.,Lee, K.K. (deposition date: 2022-06-08, release date: 2022-08-31, Last modification date: 2024-10-23)

Primary citation

Mangala Prasad, V.,Blijleven, J.S.,Smit, J.M.,Lee, K.K.
Visualization of conformational changes and membrane remodeling leading to genome delivery by viral class-II fusion machinery.
Nat Commun, 13:4772-4772, 2022

PubMed Abstract: 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.

PubMed: 35970990
DOI: 10.1038/s41467-022-32431-9

Experimental method

ELECTRON MICROSCOPY (27.2 Å)