Structure of deformed wing virus, a major honey bee pathogen

Abstract

The worldwide population of western honey bees (Apis mellifera) is under pressure from habitat loss, environmental stress, and pathogens, particularly viruses that cause lethal epidemics. Deformed wing virus (DWV) from the family Iflaviridae, together with its vector, the mite Varroa destructor, is likely the major threat to the world's honey bees. However, lack of knowledge of the atomic structures of iflaviruses has hindered the development of effective treatments against them. Here, we present the virion structures of DWV determined to a resolution of 3.1 Åusing cryo-electron microscopy and 3.8 Å by X-ray crystallography. The C-terminal extension of capsid protein VP3 folds into a globular protruding (P) domain, exposed on the virion surface. The P domain contains an Asp-His-Ser catalytic triad that is, together with five residues that are spatially close, conserved among iflaviruses. These residues may participate in receptor binding or provide the protease, lipase, or esterase activity required for entry of the virus into a host cell. Furthermore, nucleotides of the DWV RNA genome interact with VP3 subunits. The capsid protein residues involved in the RNA binding are conserved among honey bee iflaviruses, suggesting a putative role of the genome in stabilizing the virion or facilitating capsid assembly. Identifying the RNA-binding and putative catalytic sites within the DWV virion structure enables future analyses of how DWV and other iflaviruses infect insect cells and also opens up possibilities for the development of antiviral treatments.colony collapse disorder | virus | structure | Apis mellifera | honey bee

Virus found in a boreal lake links ssDNA and dsDNA viruses

“…S3 E and F). Reaching such resolution from a relatively small number of particles has been reported before, for example in the case of deformed wing virus (EMD-3570) (23). In the FLiP reconstruction, pentameric spikes (12 nm high) protrude from the 12 icosahedral vertices ( Fig.…”

“…Contrast transfer function (CTF) parameters were estimated locally using GCTF (50). The 3D structure of full particles was determined in Relion using established protocols for image classification and gold-standard structure refinement (23). As a starting model, the previously published structure of PM2 [Electron Microscopy Data Bank (EMDB) accession code EMD-1082] was used and was filtered to low resolution (40 Å) to avoid bias.…”

Development of a honey bee RNA virus vector based on the genome of Deformed wing virus

“…The Cterminus of eGFP was linked to the amino acid position "minus 6" of the proposed proteolytic cleavage peptide between the LP and VP2 (VQAKPEMDNPNPG) which is tentatively targeted by DWV 3C protease (10). The N-terminus of eGFP was fused to the LP in two configurations: either via a proposed full proteolytic cleavage peptide VQAKPEMDNPNPG present at the LP-VP2 border in the clone pDWV-L-GFP, where proteolysis takes place between the glutamate and methionine residues [10;17], or via a shorter peptide, VQAKPE, corresponding to the proposed C-terminus of the LP after proteolysis [10,17] (Figure 1). In the case of the pDWV-S-GFP construct, the linking peptide did not include the complete proposed proteolytic site and therefore this construct was expected to express LP-GFP as a fusion protein.…”

Virucides in apiculture: persistence of surrogate enterovirus under simulated field conditions

“…Physicochemical properties of both f. Iflaviridae and f. Dicistroviridae have not been fully established . However, phylogenetic analyses based on the virion structure comparing honeybee iflaviruses and dicistroviruses to picornaviruses showed that DWV and BQCV are structurally related to vertebrate picornaviruses (f. Picornaviridae ) . In general, picornaviruses are considered to be relatively resistant to chemical germicides, mainly as a consequence of the absence of the lipid envelope of virions .…”

“…17 However, phylogenetic analyses based on the virion structure comparing honeybee iflaviruses and dicistroviruses to picornaviruses showed that DWV and BQCV are structurally related to vertebrate picornaviruses (f. Picornaviridae). 18,19 In general, picornaviruses are considered to be relatively resistant to chemical germicides, mainly as a consequence of the absence of the lipid envelope of virions. 20 They are stable in the environment and able to persist on surfaces, particularly when surrounded by organic matter.…”