MURINE CORONAVIRUS PACKAGING SIGNAL CONFERS PACKAGING TO NONVIRAL RNA

Studies of defective interfering (DI) RNAs of the murine coronavirus m ouse 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-infec ted cells, they were packaged into MHV particles. Those RNA transcript s that lacked the packaging signal or those containing a mutated packa ging signal did not package efficiently. Thus, the presence of the pac kaging signal was sufficient for RNA packaging into MHV particles.