8W12

Cryo-EM structure of VP3-VP6 heterohexamer

Summary for 8W12

• Entry DOI: 10.2210/pdb8w12/pdb
• EMDB information: 43714
• Descriptor: Core protein VP3, VP6 (2 entities in total)
• Functional Keywords: bluetongue virus, capsid protein, heterohexamer, viral protein
• Biological source: Bluetongue virus (serotype 1 / isolate South Africa); More
• Total number of polymer chains: 6
• Total formula weight: 467586.88

Authors

Xia, X.,Sung, P.Y.,Martynowycz, M.W.,Gonen, T.,Roy, P.,Zhou, Z.H. (deposition date: 2024-02-14, release date: 2024-04-24, Last modification date: 2024-05-08)

Primary citation

Xia, X.,Sung, P.Y.,Martynowycz, M.W.,Gonen, T.,Roy, P.,Zhou, Z.H.
RNA genome packaging and capsid assembly of bluetongue virus visualized in host cells.
Cell, 187:2236-2249.e17, 2024

PubMed Abstract: Unlike those of double-stranded DNA (dsDNA), single-stranded DNA (ssDNA), and ssRNA viruses, the mechanism of genome packaging of dsRNA viruses is poorly understood. Here, we combined the techniques of high-resolution cryoelectron microscopy (cryo-EM), cellular cryoelectron tomography (cryo-ET), and structure-guided mutagenesis to investigate genome packaging and capsid assembly of bluetongue virus (BTV), a member of the Reoviridae family of dsRNA viruses. A total of eleven assembly states of BTV capsid were captured, with resolutions up to 2.8 Å, with most visualized in the host cytoplasm. ATPase VP6 was found underneath the vertices of capsid shell protein VP3 as an RNA-harboring pentamer, facilitating RNA packaging. RNA packaging expands the VP3 shell, which then engages middle- and outer-layer proteins to generate infectious virions. These revealed "duality" characteristics of the BTV assembly mechanism reconcile previous contradictory co-assembly and core-filling models and provide insights into the mysterious RNA packaging and capsid assembly of Reoviridae members and beyond.

PubMed: 38614100
DOI: 10.1016/j.cell.2024.03.007

Experimental method

ELECTRON MICROSCOPY (3.5 Å)