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Phage Phenomics: Physiological Approaches to Characterize Novel Viral Proteins
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Phage Phenomics: Physiological Approaches to Characterize Novel Viral Proteins

Published on: June 11, 2015

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Characterization of mycobacteriophage Adephagia cytotoxic proteins

Krista G Freeman1, Michael J Lauer1, Danny Jiang1

  • 1Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA 15260, USA.

G3 (Bethesda, Md.)
|July 20, 2024
PubMed

Insights

Mycobacterium phage Adephagia gene functions were explored. Many non-structural genes showed toxicity in Mycobacterium smegmatis, revealing new insights into phage biology and potential applications.

Area of Science:

  • Microbiology
  • Virology
  • Molecular Biology

Background:

  • Mycobacterium phage Adephagia is a temperate siphovirus infecting Mycobacterium species.
  • Its genome encodes 94 predicted proteins, with many non-structural genes lacking defined functions.
  • Understanding these genes is crucial for phage biology and potential therapeutic applications.

Purpose of the Study:

  • To determine Adephagia gene expression patterns during lytic and lysogenic growth.
  • To assign functions to uncharacterized non-structural genes using toxicity assays and structural predictions.
  • To characterize the Adephagia HicAB-like toxin-antitoxin system.

Main Methods:

  • Gene expression analysis during lytic and lysogenic cycles.
  • Expression of 66 non-structural genes in Mycobacterium smegmatis to assess toxic phenotypes.
  • Structural prediction analysis for gene function assignment.
  • Characterization of the toxin-antitoxin system (gp91 and gp90).

Main Results:

  • 25 out of 66 tested non-structural genes (38%) exhibited toxicity or growth inhibition in M. smegmatis.
  • Some toxic genes are implicated in DNA metabolism or regulation, while others remain functionally unknown.
  • The Adephagia toxin-antitoxin system was characterized, with the gp90 antitoxin shown to be essential for growth and to neutralize gp91 toxicity.

Conclusions:

  • Mycobacterium phage Adephagia possesses numerous non-structural genes with significant impacts on host cell growth.
  • The study assigned potential functions to previously uncharacterized genes and elucidated the role of a toxin-antitoxin system.
  • These findings enhance our understanding of phage-host interactions and Adephagia biology.
Keywords:
cytotoxic genesmycobacteriophagetoxin–antitoxin

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