7xr2
From Proteopedia
3.1 Angstrom cryoEM icosahedral reconstruction of mud crab reovirus
Structural highlights
FunctionPublication Abstract from PubMedInfecting a wide range of hosts, members of Reovirales (formerly Reoviridae) consist of a genome with different numbers of segmented double stranded RNAs (dsRNA) encapsulated by a proteinaceous shell and carry out genome replication and transcription inside the virion. Several cryo-electron microscopy (cryo-EM) structures of reoviruses with 9, 10 or 11 segmented dsRNA genomes have revealed insights into genome arrangement and transcription. However, the structure and genome arrangement of 12-segmented Reovirales members remain poorly understood. Using cryo-EM, we determined the structure of mud crab reovirus (MCRV), a 12-segmented dsRNA virus that is a putative member of Reovirales in the non-turreted Sedoreoviridae family, to near-atomic resolutions with icosahedral symmetry (3.1 A) and without imposing icosahedral symmetry (3.4 A). These structures revealed the organization of the major capsid proteins in two layers: an outer T = 13 layer consisting of VP12 trimers and unique VP11 clamps, and an inner T = 1 layer consisting of VP3 dimers. Additionally, ten RNA dependent RNA polymerases (RdRp) were well resolved just below the VP3 layer but were offset from the 5-fold axes and arranged with D5 symmetry, which has not previously been seen in other members of Reovirales. The N-termini of VP3 were shown to adopt four unique conformations; two of which anchor the RdRps, while the other two conformations are likely involved in genome organization and capsid stability. Taken together, these structures provide a new level of understanding for capsid stabilization and genome organization of segmented dsRNA viruses. The structure of a 12-segmented dsRNA reovirus: New insights into capsid stabilization and organization.,Zhang Q, Gao Y, Baker ML, Liu S, Jia X, Xu H, He J, Kaelber JT, Weng S, Jiang W PLoS Pathog. 2023 Apr 21;19(4):e1011341. doi: 10.1371/journal.ppat.1011341. , eCollection 2023 Apr. PMID:37083840[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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