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Role of the host cell in bacteriophage T4 development. I. Characterization of host mutants that block T4 head

H R Revel, B L Stitt, I Lielausis

    Journal of Virology
    |January 1, 1980
    PubMed

    Insights

    Bacteriophage T4 assembly requires host factors interacting with phage proteins gp31 and gp23. Mutations in these phage genes or host factors reveal specific interactions essential for initiating T4 head formation.

    Area of Science:

    • Molecular Biology
    • Virology
    • Genetics

    Background:

    • Bacteriophage T4 infection relies on host cell machinery.
    • Understanding host-bacteriophage interactions is crucial for viral replication studies.

    Purpose of the Study:

    • Investigate the role of host factors in bacteriophage T4 infection.
    • Identify specific host components essential for T4 phage assembly.

    Main Methods:

    • Selection and classification of over 600 host-defective bacterial mutants.
    • Analysis of T4 phage growth patterns with compensating mutations (go mutants).
    • In vitro complementation, electron microscopy, and SDS-PAGE to study T4 assembly.

    Main Results:

    • Host mutants were classified into seven groups based on T4 growth defects.
    • Assembly-defective mutants block T4 capsid formation before recognizable structure assembly.
    • Compensating T4 mutations occurred in gene 31 or the major capsid protein gene (gene 23).

    Conclusions:

    • Host factors are essential for initiating T4 head assembly, interacting with phage proteins gp31 and gp23.
    • These interactions are allele-specific, suggesting direct involvement in protein complexes.
    • At least three components—gp31, gp23, and host factors—are necessary for T4 head assembly initiation.

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