Coronavirus polyprotein processing

  • S. R. Weiss
  • S. A. Hughes
  • P. J. Bonilla
  • J. D. Turner
  • J. L. Leibowitz
  • M. R. Denison
Conference paper
Part of the Archives of Virology Supplementum book series (ARCHIVES SUPPL, volume 9)


MHV gene 1 contains two ORFs in different reading frames. Translation proceeds through ORF 1a into ORF 1b via a translational frame-shift. ORF 1a potentially encodes three protease activities, two papain-like activities and one poliovirus 3C-like activity. Of the three predicted activities, only the more amino terminal papain-like domain has been demonstrated to have protease activity. ORF 1a polypeptides have been detected in infected cells by the use of antibodies. The order of polypeptides encoded from the 5′ end of the ORF is p28, p65, p290. p290 is processed into p240 and p50. Processing of ORF1a polypeptides differs during cell free translation of genome RNA and in infected cells, suggesting that different proteases may be active under different conditions. Two RNA negative mutants of MHV-A59 express greatly reduced amounts of p28 and p65 at the non-permissive temperature. These mutants may have defects in one or more viral protease activities. ORF 1b, highly conserved between MHV and IBV, potentially contains polymerase, helicase and zinc finger domains. None of these activities have yet been demonstrated. ORF 1b polypeptides have yet been detected in infected cells.


Infectious Bronchitis Virus Zinc Finger Domain Mouse Hepatitis Virus Cell Free Translation Coronavirus Mouse Hepatitis Virus 
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  1. 1.
    Pachuk CJ, Bredenbeek PJ, Zoltick PW, Spaan WJM, Weiss SR (1989) Molecular cloning of the gene encoding the putative polymerase of mouse hepatitis virus strain A59. Virology 171: 141–148PubMedCrossRefGoogle Scholar
  2. 2.
    Lee HJ, Shieh CK, Gorbalenya AE, Koonin EV, LaMonica N, Tuler J, Bagdzhadzhyan A, Lai MMC (1991) The complete sequence of the murine Coronavirus gene 1 encoding the putative protease and RNA polymerase. Virology 180: 567–582PubMedCrossRefGoogle Scholar
  3. 3.
    Spaan WJM, Cavanagh D, Horzinek MC (1988) Coronaviruses. Structure and genome expression. J Gen Virol 69: 2939–2952PubMedCrossRefGoogle Scholar
  4. 4.
    Sethna PB, Hung S-L, Brian DA (1989) Coronavirus subgenomic minus-strand RNAs and the potential for RNA replicons. Proc Natl Acad Sci USA 86: 5626–5630PubMedCrossRefGoogle Scholar
  5. 5.
    Boursnell MEG, Brown TDK, Foulds IJ, Green PH, Tomley FM, Binns MM (1987) Completion of the sequence of the genome of the Coronavirus avian infectious bronchitis virus. J Gen Virol 68: 57–77PubMedCrossRefGoogle Scholar
  6. 6.
    Bredenbeek PJ, Pachuk CJ, Noten AFH, Charite J, Luytjes W, Weiss SR, Spaan WJM (1990) The primary structure and expression of the second open reading frame of the polymerase gene of the Coronavirus MHV-A59; a highly conserved polymerase is expressed by an efficient ribosomal frameshifting mechanism. Nucleic Acids Res 18: 1825–1832PubMedCrossRefGoogle Scholar
  7. 7.
    Brierly I, Boursnell MEG, Binns MM, Bilimoria B, Blok VC, Brown TDK, Inglis SC (1987) An efficient ribosomal frame-shifting signal in the polymerase encoding region of the Coronavirus IBV. EMBO J 6: 3779–3785Google Scholar
  8. 8.
    Gorbalenya AE, Koonin EV, Lai MMC (1991) Putative papain-related thiol proteases of positive strand RNA viruses. FEBS Lett 288: 201–205PubMedCrossRefGoogle Scholar
  9. 9.
    Baker SC, Shieh CK, Chang MF, Vannier DM, Lai MMC (1989) Identification of a domain required for autoproteolytic cleavage of murine Coronavirus gene A polyprotein. J Virol 63: 3693–3699PubMedGoogle Scholar
  10. 10.
    Gorbalenya AE, Blinov VM, Donchenko AP, Koonin EV (1989) An NTP-binding domain is the most conserved seq uence in a highly diverged monophyletic group of proteins involved in positive strand RNA viral replication. J Mol Evol 28: 256–268PubMedCrossRefGoogle Scholar
  11. 11.
    Gorbalenya AE, Koonin EV, Donchenko AP, Blinov VM (1992) Coronavirus genome: prediction of putative functional domains in the non-structural polyprotein by comparative amino acid sequence analysis. Nucleic Acids Res 17: 4847–4861CrossRefGoogle Scholar
  12. 12.
    Studier WF, Rosenberg AH, Dunn JJ, Dubendorf JW (1990) Use of T7 polymerase to direct the expression of cloned genes. Methods Enzymol 185: 60–89PubMedCrossRefGoogle Scholar
  13. 13.
    Zoltick PW, Leibowitz JL, De Vries JR, Weinstock GM, Weiss SR (1989) A general method for the induction and screening of antisera for cDNA-encoded polypeptides: antibodies specific for a Coronavirus putative polymerase encoding gene. Gene 85: 413–420PubMedCrossRefGoogle Scholar
  14. 14.
    Denison MR, Perlman S (1986) Translation and processing of mouse hepatitis virus virion RNA in a cell-free system. J Virol 60: 12–18PubMedGoogle Scholar
  15. 15.
    Denison MR, Zoltick PW, Leibowitz JL, Pachuk CJ, Weiss SR (1991) Identification of polypeptides encoded in open reading frame lb of the putative polymerase gene of the murine Coronavirus mouse hepatitis virus A59. J Virol 65: 3076–3082PubMedGoogle Scholar
  16. 16.
    Denison MR, Zoltick PW, Hughes SA, Giangreco B, Olson AL, Perlman S, Leibowitz JL, Weiss SR (1992) Intracellular processing of the N-terminal ORF la proteins of the Coronavirus MHV-A59 requires multiple proteolytic events. Virology 189: 274–284PubMedCrossRefGoogle Scholar
  17. 17.
    Shaad MC, Stohlman SA, Egbert J, Lum K, Fu K, Wei T, Baric RS (1990) Genetics of mouse hepatitis virus transcription: Identification of cistrons which may function in positive and negative strand RNA synthesis. Virology 177: 634–645CrossRefGoogle Scholar

Copyright information

© Springer-Verlag 1994

Authors and Affiliations

  • S. R. Weiss
    • 1
  • S. A. Hughes
    • 1
  • P. J. Bonilla
    • 1
  • J. D. Turner
    • 1
  • J. L. Leibowitz
    • 2
  • M. R. Denison
    • 3
  1. 1.Department of MicrobiologyUniversity of Pennsylvania School of MedicinePhiladelphiaUSA
  2. 2.Department of Pathology and Laboratory MedicineUniversity of Texas Health Sciences CenterHoustonUSA
  3. 3.Department of PediatricsVanderbilt University School of MedicineNashvilleUSA

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