title: Structure of the Triatoma virus capsid.
abstract: The members of the Dicistroviridae family are non-enveloped positive-sense single-stranded RNA (+ssRNA) viruses pathogenic to beneficial arthropods as well as insect pests of medical importance. Triatoma virus (TrV), a member of this family, infects several species of triatomine insects (popularly named kissing bugs), which are vectors for human trypanosomiasis, more commonly known as Chagas disease. The potential use of dicistroviruses as biological control agents has drawn considerable attention in the past decade, and several viruses of this family have been identified, with their targets covering honey bees, aphids and field crickets, among others. Here, the crystal structure of the TrV capsid at 2.5 Å resolution is reported, showing that as expected it is very similar to that of Cricket paralysis virus (CrPV). Nevertheless, a number of distinguishing structural features support the introduction of a new genus (Triatovirus; type species TrV) under the Dicistroviridae family. The most striking differences are the absence of icosahedrally ordered VP4 within the infectious particle and the presence of prominent projections that surround the fivefold axis. Furthermore, the structure identifies a second putative autoproteolytic DDF motif in protein VP3, in addition to the conserved one in VP1 which is believed to be responsible for VP0 cleavage during capsid maturation. The potential meaning of these new findings is discussed.
authors.affiliation: Laboratoire de Virologie Moléculaire et Structurale, CNRS, 1 Avenue de la Terrasse, 91198 Gif-sur-Yvette CEDEX, France.
authors.forename: Gaëlle
authors.initials: G
authors.lastname: Squires
authors.forename: Joan
authors.initials: J
authors.lastname: Pous
authors.forename: Jon
authors.initials: J
authors.lastname: Agirre
authors.forename: Gabriela S
authors.initials: GS
authors.lastname: Rozas-Dennis
authors.forename: Marcelo D
authors.initials: MD
authors.lastname: Costabel
authors.forename: Gerardo A
authors.initials: GA
authors.lastname: Marti
authors.forename: Jorge
authors.initials: J
authors.lastname: Navaza
authors.forename: Stéphane
authors.initials: S
authors.lastname: Bressanelli
authors.forename: Diego M A
authors.initials: DM
authors.lastname: Guérin
authors.forename: Felix A
authors.initials: FA
authors.lastname: Rey
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D036022:Capsid Proteins / Q000737:chemistry*; D056629:Dicistroviridae / Q000737:chemistry*; D008958:Models, Molecular; D010572:Pest Control, Biological / Q000379:methods; D016415:Sequence Alignment; D014224:Triatoma / Q000821:virology*; D014961:X-Ray Diffraction
chemical_list: D036022:Capsid Proteins
keywords: Cripavirus; Dicistroviridae; TrV; Triatoma virus; X-ray crystallography; virus structure