title: Maturation of flaviviruses starts from one or more icosahedrally independent nucleation centres.
abstract: Flaviviruses assemble as fusion-incompetent immature particles and subsequently undergo conformational change leading to release of infectious virions. Flavivirus infections also produce combined 'mosaic' particles. Here, using cryo-electron tomography, we report that mosaic particles of dengue virus type 2 had glycoproteins organized into two regions of mature and immature structure. Furthermore, particles of a maturation-deficient mutant had their glycoproteins organized into two regions of immature structure with mismatching icosahedral symmetries. It is therefore apparent that the maturation-related reorganization of the flavivirus glycoproteins is not synchronized across the whole virion, but is initiated from one or more nucleation centres. Similar deviation from icosahedral symmetry might be relevant to the asymmetrical mode of genome packaging and cell entry of other viruses.
authors.affiliation: Department of Biological Sciences, 240 South Martin Jischke Drive, Purdue University, West Lafayette, Indiana 47907-2032, USA.
authors.forename: Pavel
authors.initials: P
authors.lastname: Plevka
authors.forename: Anthony J
authors.initials: AJ
authors.lastname: Battisti
authors.forename: Jiraphan
authors.initials: J
authors.lastname: Junjhon
authors.forename: Dennis C
authors.initials: DC
authors.lastname: Winkler
authors.forename: Heather A
authors.initials: HA
authors.lastname: Holdaway
authors.forename: Poonsook
authors.initials: P
authors.lastname: Keelapang
authors.forename: Nopporn
authors.initials: N
authors.lastname: Sittisombut
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Kuhn
authors.forename: Alasdair C
authors.initials: AC
authors.lastname: Steven
authors.forename: Michael G
authors.initials: MG
authors.lastname: Rossmann
mesh_terms: D000641:Ammonia / Q000494:pharmacology; D003716:Dengue Virus / Q000187:drug effects / Q000502:physiology*; D050505:Mutant Proteins / Q000737:chemistry / Q000235:genetics; D014759:Viral Envelope Proteins / Q000737:chemistry / Q000235:genetics; D014771:Virion / Q000737:chemistry* / Q000187:drug effects / Q000648:ultrastructure; D019065:Virus Assembly / Q000187:drug effects / Q000235:genetics
chemical_list: D050505:Mutant Proteins; D014759:Viral Envelope Proteins; D000641:Ammonia