title: Yeast Ty retrotransposons assemble into virus-like particles whose T-numbers depend on the C-terminal length of the capsid protein.
abstract: The virus-like particles (VLPs) produced by the yeast Ty retrotransposons are structurally and functionally related to retroviral cores. Using cryo-electron microscopy (cryo-EM) and three-dimensional (3D) reconstruction, we have examined the structures of VLPs assembled from full-length and truncated forms of the capsid structural protein. The VLPs are highly polydisperse in their radius distribution. We have found that the length of the C-terminal region of the capsid structural protein dictates the T -number, and thus the size, of the assembled particles. Each construct studied appears to assemble into at least two or three size classes, with shorter C termini giving rise to smaller particles. This assembly property provides a model for understanding the variable assembly of retroviral core proteins. The particles are assembled from trimer-clustered units and there are holes in the capsid shells.
authors.affiliation: Birkbeck College, Malet Street, London, WC1E 7HX, UK.
authors.forename: H A
authors.initials: HA
authors.lastname: AL-Khayat
authors.forename: D
authors.initials: D
authors.lastname: Bhella
authors.forename: J M
authors.initials: JM
authors.lastname: Kenney
authors.forename: J F
authors.initials: JF
authors.lastname: Roth
authors.forename: A J
authors.initials: AJ
authors.lastname: Kingsman
authors.forename: E
authors.initials: E
authors.lastname: Martin-Rendon
authors.forename: H R
authors.initials: HR
authors.lastname: Saibil
mesh_terms: D002213:Capsid / Q000648:ultrastructure; D020285:Cryoelectron Microscopy; D005656:Fungal Proteins / Q000235:genetics; D007091:Image Processing, Computer-Assisted; D010316:Particle Size; D011487:Protein Conformation; D018626:Retroelements / Q000235:genetics*; D012441:Saccharomyces cerevisiae / Q000235:genetics*
chemical_list: D005656:Fungal Proteins; D018626:Retroelements