title: Symmetry, flexibility and permeability in the structure of yeast retrotransposon virus-like particles.
abstract: The virus-like particles (VLPs) of the yeast retrotransposon Ty are genetically, structurally and functionally analogous to retroviral nucleocapsids or cores. Like retroviral cores Ty-VLPs package and possibly promote the enzyme activities for reverse transcription and integration, as well as encapsulating the RNA that is the intermediate in retrotransposition. Here we show that Ty-VLPs assemble into symmetrical structures across a broad distribution of particle sizes. This spread of sizes violates the principle of quasi-equivalent packing. In addition, RNase accessibility experiments suggest that these particles form an open structure that does not protect the encapsulated RNA. These features distinguish Ty-VLPs from typical spherical viral capsids in both structure and function.
authors.affiliation: British Bio-technology Limited, Oxford, UK.
authors.forename: N R
authors.initials: NR
authors.lastname: Burns
authors.forename: H R
authors.initials: HR
authors.lastname: Saibil
authors.forename: N S
authors.initials: NS
authors.lastname: White
authors.forename: J F
authors.initials: JF
authors.lastname: Pardon
authors.forename: P A
authors.initials: PA
authors.lastname: Timmins
authors.forename: S M
authors.initials: SM
authors.lastname: Richardson
authors.forename: B M
authors.initials: BM
authors.lastname: Richards
authors.forename: S E
authors.initials: SE
authors.lastname: Adams
authors.forename: S M
authors.initials: SM
authors.lastname: Kingsman
authors.forename: A J
authors.initials: AJ
authors.lastname: Kingsman
mesh_terms: D004251:DNA Transposable Elements; D005814:Genes, Viral; D007091:Image Processing, Computer-Assisted; D008854:Microscopy, Electron; D012331:RNA, Fungal / Q000235:genetics; D012190:Retroviridae / Q000235:genetics* / Q000648:ultrastructure; D012441:Saccharomyces cerevisiae / Q000235:genetics*; D014158:Transcription, Genetic; D014461:Ultracentrifugation
chemical_list: D004251:DNA Transposable Elements; D012331:RNA, Fungal