title: Mechanisms of assembly and genome packaging in an RNA virus revealed by high-resolution cryo-EM.
abstract: Cowpea mosaic virus is a plant-infecting member of the Picornavirales and is of major interest in the development of biotechnology applications. Despite the availability of >100 crystal structures of Picornavirales capsids, relatively little is known about the mechanisms of capsid assembly and genome encapsidation. Here we have determined cryo-electron microscopy reconstructions for the wild-type virus and an empty virus-like particle, to 3.4 Å and 3.0 Å resolution, respectively, and built de novo atomic models of their capsids. These new structures reveal the C-terminal region of the small coat protein subunit, which is essential for virus assembly and which was missing from previously determined crystal structures, as well as residues that bind to the viral genome. These observations allow us to develop a new model for genome encapsidation and capsid assembly.
authors.affiliation: Astbury Centre for Structural Molecular Biology, University of Leeds, Mount Preston Street, Leeds LS2 9JT, UK.
authors.forename: Emma L
authors.initials: EL
authors.lastname: Hesketh
authors.affiliation: Department of Biological Chemistry, John Innes Centre, Norwich Research Park, Colney, Norwich NR4 7UH, UK.
authors.forename: Yulia
authors.initials: Y
authors.lastname: Meshcheriakova
authors.affiliation: Astbury Centre for Structural Molecular Biology, University of Leeds, Mount Preston Street, Leeds LS2 9JT, UK.
authors.forename: Kyle C
authors.initials: KC
authors.lastname: Dent
authors.affiliation: Department of Biological Chemistry, John Innes Centre, Norwich Research Park, Colney, Norwich NR4 7UH, UK.
authors.forename: Pooja
authors.initials: P
authors.lastname: Saxena
authors.affiliation: Astbury Centre for Structural Molecular Biology, University of Leeds, Mount Preston Street, Leeds LS2 9JT, UK.
authors.forename: Rebecca F
authors.initials: RF
authors.lastname: Thompson
authors.affiliation: Astbury Centre for Structural Molecular Biology, University of Leeds, Mount Preston Street, Leeds LS2 9JT, UK.
authors.forename: Joseph J
authors.initials: JJ
authors.lastname: Cockburn
authors.affiliation: Department of Biological Chemistry, John Innes Centre, Norwich Research Park, Colney, Norwich NR4 7UH, UK.
authors.forename: George P
authors.initials: GP
authors.lastname: Lomonossoff
authors.affiliation: Astbury Centre for Structural Molecular Biology, University of Leeds, Mount Preston Street, Leeds LS2 9JT, UK.
authors.forename: Neil A
authors.initials: NA
authors.lastname: Ranson
mesh_terms: D017798:Comovirus / Q000235:genetics* / Q000502:physiology*; D020285:Cryoelectron Microscopy; D016678:Genome; D008958:Models, Molecular; D009690:Nucleic Acid Conformation; D012367:RNA, Viral / Q000502:physiology*; D019065:Virus Assembly / Q000502:physiology*
chemical_list: D012367:RNA, Viral