title: A domain at the 3' end of the polymerase gene is essential for encapsidation of coronavirus defective interfering RNAs.
abstract: Two murine hepatitis virus strain A59 defective interfering (DI) RNAs were generated by undiluted virus passages. The DI RNAs were encapsidated efficiently. The smallest DI particle, DI-a, contained a 5.5-kb RNA consisting of the following three noncontiguous regions from the MHV-A59 genome, which were joined in frame: the 5'-terminal 3.9 kb, a 798-nucleotide fragment from the 3' end of the polymerase gene, and the 3'-terminal 805 nucleotides. A full-length cDNA clone of the DI-a genome was constructed and cloned downstream of the bacteriophage T7 promoter. Transcripts derived from this clone, pMIDI, were used for transfection of MHV-A59-infected cells and found to be amplified and packaged. Deletion analysis of pMIDI allowed us to identify a 650-nucleotide region derived from the 3' end of the second open reading frame of the polymerase gene that was required for efficient encapsidation.
authors.affiliation: Department of Virology, Faculty of Medicine, Leiden University, The Netherlands.
authors.forename: R G
authors.initials: RG
authors.lastname: van der Most
authors.forename: P J
authors.initials: PJ
authors.lastname: Bredenbeek
authors.forename: W J
authors.initials: WJ
authors.lastname: Spaan
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002478:Cells, Cultured; D003001:Cloning, Molecular; D003332:Coronaviridae / Q000235:genetics* / Q000254:growth & development; D003588:Cytopathogenic Effect, Viral; D012321:DNA-Directed RNA Polymerases / Q000235:genetics*; D003673:Defective Viruses / Q000235:genetics*; D051379:Mice; D008969:Molecular Sequence Data; D016296:Mutagenesis; D016366:Open Reading Frames; D011401:Promoter Regions, Genetic; D012367:RNA, Viral / Q000737:chemistry*; D015183:Restriction Mapping; D013604:T-Phages / Q000235:genetics; D014779:Virus Replication / Q000235:genetics*
chemical_list: D012367:RNA, Viral; D012321:DNA-Directed RNA Polymerases