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A protein, VPg, covalently linked to 36S calicivirus RNA

F L Schaffer, D W Ehresmann, M K Fretz

    The Journal of General Virology
    |March 1, 1980
    PubMed

    Insights

    San Miguel sea lion virus type 2 (SMSV-2) RNA contains a VPg protein covalently linked to the genome. This protein, essential for viral replication, was found to have two phosphates per genome and a molecular weight of 15,000.

    Area of Science:

    • Virology
    • Molecular Biology
    • Biochemistry

    Background:

    • San Miguel sea lion virus (SMSV) is an important marine calicivirus.
    • Understanding the structure and function of viral proteins is crucial for antiviral development.

    Purpose of the Study:

    • To identify and characterize proteins associated with the 36S viral RNA of SMSV-2.
    • To investigate the role of the VPg protein in SMSV-2 RNA.

    Main Methods:

    • Proteins associated with 36S viral RNA from SMSV-2 infected Vero cells were labeled with 125I.
    • Deproteinization techniques were used to assess protein-RNA linkage.
    • VPg was labeled with 32P to quantify its presence on the viral RNA.

    Main Results:

    • A protein, designated VPg, was found to remain linked to the 36S RNA after deproteinization.
    • VPg labeled with 32P was detected on purified SMSV-2 virion RNA.
    • The amount of 32P label suggested two phosphates per genome, indicating VPg's role in RNA initiation or replication.
    • The estimated molecular weight of SMSV-2 VPg was 15,000 Daltons.

    Conclusions:

    • SMSV-2 possesses a VPg protein covalently attached to its RNA genome.
    • VPg is likely involved in the replication of SMSV-2 RNA.
    • The characterization of SMSV-2 VPg provides insights into the replication mechanisms of marine caliciviruses.

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