title: 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 familyIflaviridae, together with its vector, the miteVarroa 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 Å using 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.
authors.affiliation: Structural Virology, Central European Institute of Technology, Masaryk University, 62500 Brno, Czech Republic.
authors.forename: Karel
authors.initials: K
authors.lastname: Škubník
authors.affiliation: Structural Virology, Central European Institute of Technology, Masaryk University, 62500 Brno, Czech Republic.
authors.forename: Jiří
authors.initials: J
authors.lastname: Nováček
authors.affiliation: Structural Virology, Central European Institute of Technology, Masaryk University, 62500 Brno, Czech Republic.
authors.forename: Tibor
authors.initials: T
authors.lastname: Füzik
authors.affiliation: Department of Zoology, Fishery, Hydrobiology, and Apidology, Faculty of Agronomy, Mendel University in Brno, 613 00 Brno, Czech Republic.
authors.forename: Antonín
authors.initials: A
authors.lastname: Přidal
authors.affiliation: Institute of Biology/Zoology, Martin Luther University Halle-Wittenberg, 06120 Halle, Germany.
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Paxton
authors.affiliation: Structural Virology, Central European Institute of Technology, Masaryk University, 62500 Brno, Czech Republic; pavel.plevka@ceitec.muni.cz.
authors.forename: Pavel
authors.initials: P
authors.lastname: Plevka
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001516:Bees / Q000821:virology*; D002213:Capsid / Q000648:ultrastructure; D036022:Capsid Proteins / Q000737:chemistry / Q000648:ultrastructure; D020285:Cryoelectron Microscopy; D007091:Image Processing, Computer-Assisted; D007304:Insect Viruses / Q000648:ultrastructure*; D008958:Models, Molecular; D011487:Protein Conformation; D000072417:Protein Domains; D012328:RNA Viruses / Q000648:ultrastructure*; D014771:Virion / Q000648:ultrastructure
chemical_list: D036022:Capsid Proteins
keywords: Apis mellifera; colony collapse disorder; honey bee; structure; virus