Murine coronavirus packaging signal confers packaging to nonviral RNA

Abstract

Studies of defective interfering (DI) RNAs of the murine coronavirus mouse hepatitis virus (MHV) suggest that a 69-nucleotide-long packaging signal is necessary for MHV genomic RNA packaging into MHV particles. In this study we showed that when RNA transcripts that consisted of a non-MHV sequence and the packaging signal were expressed in MHV-infected cells, they were packaged into MHV particles. Those RNA transcripts that lacked the packaging signal or those containing a mutated packaging signal did not package efficiently. Thus, the presence of the packaging signal was sufficient for RNA packaging into MHV particles.