The 5'-end sequence of the murine coronavirus genome: implications for multiple fusion sites in leader-primed transcription - PubMed (original) (raw)

The 5'-end sequence of the murine coronavirus genome: implications for multiple fusion sites in leader-primed transcription

C K Shieh et al. Virology. 1987 Feb.

Abstract

The coronavirus leader-primed transcription model proposes that free leader RNA species derived from the 5'-end of the genomic RNA are utilized as a primer for the transcription of subgenomic mRNAs. To elucidate the precise mechanism of leader-priming, we cloned and sequenced the 5'-end of the mouse hepatitis virus genomic RNA. The 5'-terminal sequences are identical to the leader sequences present at the 5'-end of the subgenomic mRNAs. Two possible hairpin loop structures and an AU-rich region around the 3'-end of the leader sequence may provide the termination site for leader RNA synthesis. The comparison of 5'-end genomic sequences and the intergenic start sites for mRNA transcription revealed that there are homologous regions of 7-18 nucleotides at the putative leader/body junction sites. Some intergenic regions contain a mismatching nucleotide within this homologous region. We propose that free leader RNA binds to the intergenic region due to this homology and is cleaved at the mismatching nucleotide before serving as a primer. Thus, the free leader RNA species may be longer than the leader sequences in the subgenomic mRNAs and different mRNAs may have different leader/body junction sites.

PubMed Disclaimer

Similar articles

Cited by

References

    1. Armstrong J., Niemann H., Smeekens S., Rottier P., Warren G. Sequence and topology of a model intracellular membrane protein, E1 glycoprotein, from a coronavirus. Nature (London) 1984;308:751–752. - PMC - PubMed
    1. Baric R.S., Shieh C.K., Stohlman S.A., Lai M.M.C. Analysis of intracellular small RNAs of mouse hepatitis virus: Evidence for discontinuous transcription. Virology. 1987;156:342–354. - PMC - PubMed
    1. Baric R.S., Stohlman S.A., Lai M.M.C. Characterization of replicative intermediate RNA of mouse hepatitis virus: Presence of leader RNA sequences on nascent chains. J. Virol. 1983;48:633–640. - PMC - PubMed
    1. Baric R.S., Stohlman S.A., Razavi M.K., Lai M.M.C. Characterization of leader-related small RNAs in coronavirus-infected cells: Further evidence for leader-primed mechanism of transcription. Virus Res. 1985;3:19–33. - PMC - PubMed
    1. Brayton P.R., Ganges R.G., Stohlman S.A. Host cell nuclear function and murine hepatitis virus replication. J. Gen. Virol. 1981;56:457–460. - PubMed

Publication types

MeSH terms

Substances

LinkOut - more resources