title: Identification of the putative RNA polymerase of Cryphonectria hypovirus in a solubilized replication complex.
abstract: Hypovirulence of the pathogenic fungus Cryphonectria parasitica, caused by the unencapsidated viral double-stranded RNA of Cryphonectria hypovirus (CHV1), provides a means for biological control of chestnut blight. We report here the isolation of a replication complex of the virus solubilized from host membranes. The conserved regions of the putative RNA polymerase encoded by strain CHV1-713 were cloned and expressed, and the recombinant protein was purified and used to produce polyclonal antibodies. The CHV1 replication complex was solubilized from a membrane fraction of CHV1-infected C. parasitica hyphae. Antibodies raised against the putative viral polymerase reacted on a Western immunoblot with an 87-kDa polypeptide of the replication complex but not with comparable preparations from an isogenic uninfected strain. Analysis of the polypeptide composition of the complex by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and silver staining revealed a number of other polypeptides along with the double-stranded RNA of the virus. We conclude that this 87-kDa polypeptide is the putative RNA polymerase encoded on open reading frame B of CHV1.
authors.affiliation: Department of Plant Pathology and Microbiology, Texas A&M University, College Station 77843-2132.
authors.forename: T
authors.initials: T
authors.lastname: Fahima
authors.forename: Y
authors.initials: Y
authors.lastname: Wu
authors.forename: L
authors.initials: L
authors.lastname: Zhang
authors.forename: N K
authors.initials: NK
authors.lastname: Van Alfen
mesh_terms: D015153:Blotting, Western; D012321:DNA-Directed RNA Polymerases / Q000737:chemistry*; D005658:Fungi; D046911:Macromolecular Substances; D012328:RNA Viruses / Q000737:chemistry*; D012330:RNA, Double-Stranded; D014779:Virus Replication
chemical_list: D046911:Macromolecular Substances; D012330:RNA, Double-Stranded; D012321:DNA-Directed RNA Polymerases