title: A positive-strand RNA virus replication complex parallels form and function of retrovirus capsids.
abstract: We show that brome mosaic virus (BMV) RNA replication protein 1a, 2a polymerase, and a cis-acting replication signal recapitulate the functions of Gag, Pol, and RNA packaging signals in conventional retrovirus and foamy virus cores. Prior to RNA replication, 1a forms spherules budding into the endoplasmic reticulum membrane, sequestering viral positive-strand RNA templates in a nuclease-resistant, detergent-susceptible state. When expressed, 2a polymerase colocalizes in these spherules, which become the sites of viral RNA synthesis and retain negative-strand templates for positive-strand RNA synthesis. These results explain many features of replication by numerous positive strand RNA viruses and reveal that these viruses, reverse transcribing viruses, and dsRNA viruses share fundamental similarities in replication and may have common evolutionary origins.
authors.affiliation: Institute for Molecular Virology and Howard Hughes Medical Institute, University of Wisconsin, Madison, Madison, WI 53706, USA.
authors.forename: Michael
authors.initials: M
authors.lastname: Schwartz
authors.forename: Jianbo
authors.initials: J
authors.lastname: Chen
authors.forename: Michael
authors.initials: M
authors.lastname: Janda
authors.forename: Michael
authors.initials: M
authors.lastname: Sullivan
authors.forename: Johan
authors.initials: J
authors.lastname: den Boon
authors.forename: Paul
authors.initials: P
authors.lastname: Ahlquist
mesh_terms: D017795:Bromovirus / Q000235:genetics* / Q000378:metabolism / Q000502:physiology; D002213:Capsid / Q000235:genetics* / Q000378:metabolism; D046911:Macromolecular Substances; D008954:Models, Biological; D012367:RNA, Viral / Q000235:genetics* / Q000378:metabolism; D014764:Viral Proteins / Q000235:genetics* / Q000378:metabolism; D014779:Virus Replication; D015003:Yeasts / Q000235:genetics / Q000378:metabolism / Q000648:ultrastructure
chemical_list: D046911:Macromolecular Substances; D012367:RNA, Viral; D014764:Viral Proteins