title: An unusual structure at one end of potato potyvirus particles.
abstract: The particles of potato virus Y (PVY) and potato virus A (PVA) potyviruses are helically constructed filaments that are thought to contain a single type of coat protein subunit. Examination of negatively stained virions by electron microscopy reveals flexuous rod-shaped particles with no obvious terminal structures. It is known that some helically constructed rod-shaped virus particles incorporate additional minor protein components, which form stable complexes that mediate particle disassembly, movement or transmission by vectors. Some of this information has been obtained using imaging techniques such as atomic force microscopy. The particles of PVY and PVA were examined by atomic force microscopy and immunogold labelling electron microscopy. Our results show that some of the potyvirus particles contain a protruding tip at one end of the virus particles, which is presumably associated with the 5'-end of viral RNA. The tip contains the virus-encoded proteins genome-linked protein and helper-component proteinase. The composition and possible roles of the terminal tip structures in virus biology are discussed.
authors.affiliation: Scottish Crop Research Institute, Invergowrie, Dundee DD2 5DA, UK.
authors.forename: Lesley
authors.initials: L
authors.lastname: Torrance
authors.forename: Igor A
authors.initials: IA
authors.lastname: Andreev
authors.forename: Rasa
authors.initials: R
authors.lastname: Gabrenaite-Verhovskaya
authors.forename: Graham
authors.initials: G
authors.lastname: Cowan
authors.forename: Kristiina
authors.initials: K
authors.lastname: Mäkinen
authors.forename: Michael E
authors.initials: ME
authors.lastname: Taliansky
mesh_terms: D007150:Immunohistochemistry; D018625:Microscopy, Atomic Force; D017800:Potyvirus / Q000737:chemistry* / Q000378:metabolism; D011487:Protein Conformation; D014764:Viral Proteins / Q000737:chemistry* / Q000378:metabolism / Q000648:ultrastructure*
chemical_list: D014764:Viral Proteins