Diversity in bacterial lysis systems: bacteriophages show the way

Authors

  • Maria João Catalão,

    1. Centro de Patogénese Molecular, Unidade dos Retrovírus e Infecções Associadas, Faculty of Pharmacy, University of Lisbon, Lisbon, Portugal
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  • Filipa Gil,

    1. Centro de Patogénese Molecular, Unidade dos Retrovírus e Infecções Associadas, Faculty of Pharmacy, University of Lisbon, Lisbon, Portugal
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  • José Moniz-Pereira,

    1. Centro de Patogénese Molecular, Unidade dos Retrovírus e Infecções Associadas, Faculty of Pharmacy, University of Lisbon, Lisbon, Portugal
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  • Carlos São-José,

    1. Centro de Patogénese Molecular, Unidade dos Retrovírus e Infecções Associadas, Faculty of Pharmacy, University of Lisbon, Lisbon, Portugal
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  • Madalena Pimentel

    Corresponding author
    • Centro de Patogénese Molecular, Unidade dos Retrovírus e Infecções Associadas, Faculty of Pharmacy, University of Lisbon, Lisbon, Portugal
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Correspondence: Madalena Pimentel, Centro de Patogénese Molecular, Unidade dos Retrovírus e Infecções Associadas, Faculty of Pharmacy, University of Lisbon, Av. Prof. Gama Pinto, 1649-003 Lisbon, Portugal. Tel.: +351 217946400; fax: +351 217934212; e-mail: mpimentel@ff.ul.pt

Abstract

Bacteriophages have developed multiple host cell lysis strategies to promote release of descendant virions from infected bacteria. This review is focused on the lysis mechanisms employed by tailed double-stranded DNA bacteriophages, where new developments have recently emerged. These phages seem to use a least common denominator to induce lysis, the so-called holin-endolysin dyad. Endolysins are cell wall-degrading enzymes whereas holins form ‘holes’ in the cytoplasmic membrane at a precise scheduled time. The latter function was long viewed as essential to provide a pathway for endolysin escape to the cell wall. However, recent studies have shown that phages can also exploit the host cell secretion machinery to deliver endolysins to their target and subvert the bacterial autolytic arsenal to effectively accomplish lysis. In these systems the membrane-depolarizing holin function still seems to be essential to activate secreted endolysins. New lysis players have also been uncovered that promote degradation of particular bacterial cell envelopes, such as that of mycobacteria.

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