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Defining Substrate Specificities for Lipase and Phospholipase Candidates
08:59

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Published on: November 23, 2016

The lytic cassette of mycobacteriophage Ms6 encodes an enzyme with lipolytic activity

Filipa Gil1, Maria João Catalão1, José Moniz-Pereira1

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

Microbiology (Reading, England)
|May 3, 2008
PubMed

Insights

This study identifies LysB, a novel lipolytic enzyme encoded by mycobacteriophage Ms6. This bacteriophage protein exhibits esterase activity, offering new insights into phage-host interactions and lysis mechanisms.

Area of Science:

  • Microbiology
  • Molecular Biology
  • Enzymology

Background:

  • Bacteriophages employ endolysin-holin systems for bacterial host lysis.
  • Some bacteriophages encode additional proteins within their lysis modules.
  • The function of these additional lysis proteins is often uncharacterized.

Purpose of the Study:

  • To characterize the function of the lysB gene product from mycobacteriophage Ms6.
  • To investigate the enzymatic activity and properties of the LysB protein.
  • To explore the potential role of LysB in bacteriophage-mediated bacterial lysis.

Main Methods:

  • Sequence analysis of the lysB gene and deduced LysB protein.
  • Biochemical assays to screen for lipolytic and esterase activity using various substrates.
  • Kinetic analysis of recombinant His(6)-LysB activity on p-nitrophenyl esters.
  • Determination of optimal temperature, pH, and cofactor requirements for LysB activity.

Main Results:

  • LysB possesses conserved motifs indicative of lipolytic activity.
  • Biochemical screening confirmed LysB's esterase and lipase activity.
  • Recombinant His(6)-LysB hydrolyzed a range of p-nitrophenyl esters (C4-C18), with higher affinity for longer chains (C16, C18).
  • Optimal LysB activity was observed at 23°C and pH 7.5-8.0, enhanced by Ca(2+) and Mn(2+).

Conclusions:

  • LysB is the first described bacteriophage-encoded protein with confirmed lipolytic activity.
  • LysB's specific activity suggests a potential role in modifying mycobacterial host cell envelopes during phage infection.
  • The discovery of LysB expands our understanding of bacteriophage lysis mechanisms and highlights potential host-specific adaptations.

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