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[The structural protein Gag of the gypsy retrovirus forms virus-like particles in the bacterial cell]

B V Semin, L A Ivanova, V I Popenko

    Molekuliarnaia Biologiia
    |July 28, 2011
    PubMed

    Insights

    The gypsy retrovirus Gag protein lacks typical motifs and has two potential start sites. Bacterial expression showed both variants form virus-like particles without eukaryotic factors.

    Area of Science:

    • * Virology
    • * Molecular Biology
    • * Drosophila melanogaster research

    Background:

    • * The gypsy retrovirus Gag protein's amino acid sequence lacks canonical vertebrate retroviral motifs.
    • * Its open reading frame presents two potential initiation codons for protein translation.

    Purpose of the Study:

    • * To investigate the assembly of gypsy Gag protein variants into virus-like particles.
    • * To determine if particle formation occurs in a bacterial system, independent of eukaryotic factors.

    Main Methods:

    • * Design and construction of expression vectors for two theoretical gypsy Gag variants.
    • * Expression of Gag variants in bacterial cells.
    • * Analysis of particle formation by the expressed Gag proteins.

    Main Results:

    • * Both theoretical gypsy Gag variants were successfully expressed in bacterial cells.
    • * Both variants demonstrated the ability to form globular particles.
    • * Particle formation occurred in the absence of eukaryotic cellular factors.

    Conclusions:

    • * The gypsy retrovirus Gag protein can self-assemble into virus-like particles.
    • * Bacterial expression systems are suitable for studying gypsy Gag assembly.
    • * The unique features of gypsy Gag do not preclude particle formation.

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