| Institution: | a Unidad de Biofísica (CSIC-UPV/EHU), Barrio Sarriena S/N, 48940, Leioa, Bizkaia, Spainb Servicio General de Proteómica (SGIker), Universidad del País Vasco (UPV/EHU), 48940 Leioa, Spainc Departamento de Bioquímica y Biologia Molecular, Universidad del País Vasco (UPV/EHU), 48940 Leioa, Spaind CIC-BioGUNE, Proteomic plataform, CIBERehd, Proteored, Parque Tecnológico Bizkaia, Ed800, 48160 Derio, Bizkaia, Spaine Centro de Estudios Parasitológicos y de Vectores (CEPAVE) and Centro Regional de Investigaciones Científicas y Transferencia Tecnológicas La Rioja (CRILAR), 2#584 (1900) La Plata, Argentinaf Laboratoire de Microscopie Electronique Structurale, Institut de Biologie Structurale Jean-Pierre Ebel, UMR 5075 CEA-CNRS-UJF, 41, rue Jules Horowitz, F-38027 Grenoble, Cedex 1, Franceg Unité de Virologie Structurale, CNRS URA 3015, Départment de Virologie, Institut Pasteur, 25 rue du Docteur Roux, 75724 Paris Cedex 15, Franceh Fundación Biofísica Bizkaia, B Sarriena S/N, 48940 Leioa, Bizkaia, Spain |
| Abstract: | Triatoma virus (TrV) is a non-enveloped + ssRNA virus belonging to the insect virus family Dicistroviridae. Mass spectrometry (MS) and gel electrophoresis were used to detect the previously elusive capsid protein VP4. Its cleavage sites were established by sequencing the N-terminus of the protein precursor and MS, and its stoichiometry with respect to the other major capsid proteins (VP1-3) was found to be 1:1. We also characterized the polypeptides comprising the naturally occurring non-infectious empty capsids, i.e., RNA-free TrV particles. The empty particles were composed of VP0-VP3 plus at least seven additional polypeptides, which were identified as products of the capsid precursor polyprotein. We conclude that VP4 protein appears as a product of RNA encapsidation, and that defective processing of capsid proteins precludes genome encapsidation. |
