title: Self-assembly of a viral molecular machine from purified protein and RNA constituents.
abstract: We present the assembly of the polymerase complex (procapsid) of a dsRNA virus from purified recombinant proteins. This molecular machine packages and replicates viral ssRNA genomic precursors in vitro. After addition of an external protein shell, these in vitro self-assembled viral core particles can penetrate the host plasma membrane and initiate a productive infection. Thus, a viral procapsid has been assembled and rendered infectious using purified components. Using this system, we have studied the mechanism of assembly of the common dsRNA virus shell and the incorporation of a symmetry mismatch within an icosahedral capsid. Our work demonstrates that this molecular machine, self-assembled under defined conditions in vitro, can function in its natural environment, the cell cytoplasm.
authors.affiliation: Department of Biosciences, University of Helsinki, 00014 Helsinki, Finland.
authors.forename: M M
authors.initials: MM
authors.lastname: Poranen
authors.forename: A O
authors.initials: AO
authors.lastname: Paatero
authors.forename: R
authors.initials: R
authors.lastname: Tuma
authors.forename: D H
authors.initials: DH
authors.lastname: Bamford
mesh_terms: D002213:Capsid / Q000235:genetics / Q000378:metabolism; D017910:Cystoviridae / Q000201:enzymology* / Q000235:genetics; D003593:Cytoplasm / Q000821:virology; D012321:DNA-Directed RNA Polymerases / Q000378:metabolism*; D066298:In Vitro Techniques; D012367:RNA, Viral / Q000096:biosynthesis / Q000378:metabolism*; D013104:Spheroplasts; D014758:Viral Core Proteins / Q000378:metabolism; D014771:Virion / Q000201:enzymology* / Q000235:genetics
chemical_list: D012367:RNA, Viral; D014758:Viral Core Proteins; D012321:DNA-Directed RNA Polymerases