Structural characterization by SAXS and CryoEM of P9-1, the major viroplasm component of Mal de Río Cuarto virus (MRCV).

LLAUGER, G.; GOLDBAUM, F. A.; OTERO, L. H.; MELERO, R.; SYCZ, G.; DEL VAS, M.; HUCK-IRIART, C.; MONTI, D. E.; CARAZO, J. M.

Campinas

Encuentro; 28th Annual Users meeting LNLS/CNPEM (RAU); 2018

Scientific Committee of the 28th Annual Users Meeting of the LNLS

Structural characterization by SAXS and CryoEM of P9-1, the major viroplasmcomponent of Mal de Río Cuarto virus (MRCV)Cristián Huck-Iriart1, Roberto Melero2, Gabriela Llauger3, Demian Monti3, Gabriela Sycz4,Fernando A. Goldbaum4,5, Jose María Carazo2, Mariana del Vas3, Lisandro H. Otero4,51- Escuela de Ciencia y Tecnología, Universidad Nacional de San Martín, Buenos Aires,Argentina.2- Biocomputing Unit, National Center for Biotechnology (CSIC), Universidad AutónomaMadrid, Madrid, Spain.3- Instituto de Biotecnología, Instituto Nacional de Tecnología Agropecuaria, Hurlingham,Buenos Aires, Argentina.4- Fundación Instituto Leloir-IIBBA-CONICET; Buenos Aires, Argentina.5- Plataforma Argentina de Biología Estructural y Metabolómica PLABEM, Buenos Aires,Argentina.e-mail: chuck@unsam.edu.arMal de Río Cuarto virus (MRCV, Fijivirus, Reoviridae) causes the most important maize diseasein Argentina. The virus replicates in cytoplasmic inclusion bodies called viroplasms composed bynon-structural virus proteins P9-1 and P6. P9-1 is a 45 kDa protein that has ATPase activity, whichis able to bind ssRNA and to self-assemble giving rise to homomultimers [1,2]. In this work wewill show preliminary structural characterization of P9-1 by using two complementarytechniques: Small Angle X ray Scattering (SAXS) and Cryo-Electron Microscopy (Cryo-EM).Additional experiments included the presence of ATP and/or RNA in order to evaluate changesin the structure.According to CryoEM assays, quaternary structures consisting of 10 and 12 monomers wereobserved. Experimental SAXS patterns were fitted by using the combination of ATSAS package[3] and python scripting in order to set up each protein complex using Cryo-EM volumeinformation of the monomer as building block. Our preliminary results showed that SAXSpatterns were compatible with cylindrical objects composed by the stacking of a five subunitsring.The aim of this work is to provide structural information in order to understand the function ofP9-1 complexes in the presence of ATP and ssARN.[1] Dumón, A.D.; Argüello Caro, E.B.; Mattio, M.F.; Alemandri, M.F.; del Vas, M.; Truol, G. Bulletinof entomological research, 108(2), 232-240 (2018)[2] Maroniche, G.A.; Mongelli, V.C.; Llauger, G.; Alfonso, V.; Taboga, O.; del Vas, M. Virology,430(2), 81-89, (2012)[3] Franke, D.; Petoukhov, M.V.; Konarev, P.V.; Panjkovich, A.; Mertens, H.D.I.; Kikhney, A.G.;Haijzadeh, N.R.; Franklin, J.M.; Jeffries, C.M.; Svergun, D.I. J. Appl. Cryst 50, 1212-1225 (2017)