title: The structure of native influenza virion ribonucleoproteins.
abstract: The influenza viruses cause annual epidemics of respiratory disease and occasional pandemics, which constitute a major public-health issue. The segmented negative-stranded RNAs are associated with the polymerase complex and nucleoprotein (NP), forming ribonucleoproteins (RNPs), which are responsible for virus transcription and replication. We describe the structure of native RNPs derived from virions. They show a double-helical conformation in which two NP strands of opposite polarity are associated with each other along the helix. Both strands are connected by a short loop at one end of the particle and interact with the polymerase complex at the other end. This structure will be relevant for unraveling the mechanisms of nuclear import of parental virus RNPs, their transcription and replication, and the encapsidation of progeny RNPs into virions.
authors.affiliation: Department of Macromolecular Structure, Centro Nacional de Biotecnología [Consejo Superior de Investigaciones Cienfícas (CSIC)], Madrid, Spain.
authors.forename: Rocío
authors.initials: R
authors.lastname: Arranz
authors.forename: Rocío
authors.initials: R
authors.lastname: Coloma
authors.forename: Francisco Javier
authors.initials: FJ
authors.lastname: Chichón
authors.forename: José Javier
authors.initials: JJ
authors.lastname: Conesa
authors.forename: José L
authors.initials: JL
authors.lastname: Carrascosa
authors.forename: José M
authors.initials: JM
authors.lastname: Valpuesta
authors.forename: Juan
authors.initials: J
authors.lastname: Ortín
authors.forename: Jaime
authors.initials: J
authors.lastname: Martín-Benito
mesh_terms: D000818:Animals; D002467:Cell Nucleus / Q000378:metabolism / Q000821:virology; D020285:Cryoelectron Microscopy; D055032:Electron Microscope Tomography; D007091:Image Processing, Computer-Assisted; D053118:Influenza A Virus, H1N1 Subtype / Q000737:chemistry* / Q000502:physiology / Q000648:ultrastructure; D061985:Madin Darby Canine Kidney Cells; D008854:Microscopy, Electron; D008958:Models, Molecular; D019590:Nucleocapsid Proteins; D011487:Protein Conformation; D017433:Protein Structure, Secondary; D012367:RNA, Viral / Q000737:chemistry* / Q000378:metabolism; D016601:RNA-Binding Proteins / Q000737:chemistry / Q000378:metabolism / Q000648:ultrastructure; D012324:RNA-Dependent RNA Polymerase / Q000737:chemistry / Q000378:metabolism / Q000648:ultrastructure; D012261:Ribonucleoproteins / Q000737:chemistry* / Q000378:metabolism / Q000648:ultrastructure; D014158:Transcription, Genetic; D014758:Viral Core Proteins / Q000737:chemistry / Q000378:metabolism / Q000648:ultrastructure; D014764:Viral Proteins / Q000737:chemistry* / Q000378:metabolism / Q000648:ultrastructure; D014771:Virion / Q000737:chemistry* / Q000648:ultrastructure
chemical_list: C048842:NP protein, Influenza A virus; D019590:Nucleocapsid Proteins; D012367:RNA, Viral; D016601:RNA-Binding Proteins; D012261:Ribonucleoproteins; D014758:Viral Core Proteins; D014764:Viral Proteins; D012324:RNA-Dependent RNA Polymerase