Related Experiment Video

Updated: Aug 13, 2026

Applying an Inducible Expression System to Study Interference of Bacterial Virulence Factors with Intracellular Signaling
08:51

Applying an Inducible Expression System to Study Interference of Bacterial Virulence Factors with Intracellular Signaling

Published on: June 25, 2015

MazG -- a regulator of programmed cell death in Escherichia coli

Miryam Gross1, Irina Marianovsky, Gad Glaser

  • 1Department of Cellular Biochemistry and Human Genetics, The Hebrew University - Hadassah Medical School, Jerusalem, Israel.

Molecular Microbiology
|January 5, 2006
PubMed

Insights

The MazEF bacterial toxin system is regulated by MazG, which inhibits MazEF activity and depletes ppGpp. This prevents prolonged toxin effects, aiding bacterial survival during stress.

Area of Science:

  • Bacteriology
  • Molecular Biology
  • Genetics

Background:

  • The MazEF system in Escherichia coli is a chromosomal addiction module crucial for programmed cell death under stress.
  • MazEF comprises a stable toxin (MazF) targeting mRNA and a labile antitoxin (MazE).
  • MazF's cellular target is mRNA degradation, leading to cell death.

Purpose of the Study:

  • To investigate the function of the downstream gene mazG within the mazEF operon.
  • To elucidate the interaction between MazG and the MazEF toxin-antitoxin system.
  • To understand MazG's role in regulating bacterial programmed cell death.

Main Methods:

  • Analysis of mazG transcription within the mazEF polycistronic mRNA.
  • In vitro enzymatic assays to determine MazG activity and inhibition by MazEF.
  • In vivo studies to assess MazG's effect on ppGpp levels under starvation conditions.

Main Results:

  • MazG is co-transcribed with mazEF and possesses nucleotide pyrophosphohydrolase activity.
  • MazEF proteins inhibit MazG enzymatic activity by approximately 70%.
  • MazG activity in vivo leads to the depletion of guanosine 3',5'-bispyrophosphate (ppGpp).

Conclusions:

  • MazG acts as a regulatory element, limiting the detrimental effects of the MazF toxin.
  • MazG's function prevents the persistence of toxic products, optimizing bacterial survival strategies.
  • This study proposes a model where MazG modulates the MazEF addiction system's activity.

More Related Videos

Studying Copper Nanoparticle-Induced Programmed Cell Death in Bacteria08:22

Studying Copper Nanoparticle-Induced Programmed Cell Death in Bacteria

Published on: May 16, 2025

Recombinant Protein Expression, Crystallization, and Biophysical Studies of a Bacillus-conserved Nucleotide Pyrophosphorylase, BcMazG12:23

Recombinant Protein Expression, Crystallization, and Biophysical Studies of a Bacillus-conserved Nucleotide Pyrophosphorylase, BcMazG

Published on: May 16, 2017

Related Concept Videos

Stringent Response in E. coli01:23

Stringent Response in E. coli

Bacterial growth is closely tied to nutrient availability, with cells proliferating exponentially under favorable conditions and entering a stationary phase when resources become scarce. This transition is mediated by a regulatory mechanism known as the stringent response, which allows bacteria to adapt to nutrient deprivation by modulating gene expression and metabolic activity.During nutrient scarcity, intracellular amino acid levels decline. It results in the accumulation of uncharged tRNAs...
Global Regulatory Systems01:28

Global Regulatory Systems

Global regulatory systems in bacteria enable rapid and coordinated responses to environmental changes by integrating sensory inputs with gene expression, ensuring efficient adaptation to fluctuating conditions. Key global regulatory mechanisms include regulons, two-component systems, sigma factors, and secondary messengers.Regulons and Global RegulatorsA regulon is a collection of genes and operons controlled by a common global regulator. These regulators enable bacteria to prioritize resource...
Gene Regulation During Sporulation01:17

Gene Regulation During Sporulation

Sporulation is a complex developmental process that allows certain Gram-positive bacteria, such as Bacillus subtilis and Clostridium species, to survive extreme environmental conditions. This process is tightly regulated by a series of signaling cascades and transcriptional controls, ensuring the formation of a highly resistant endospore.Sporulation is triggered by unfavorable conditions, such as nutrient depletion, and is governed by a phosphorelay system. One of the sensor kinases, such as...
Other Stress Responses in Bacteria01:30

Other Stress Responses in Bacteria

Bacteria have global regulatory systems that control several types of stress mechanisms. These include Pho regulon and the heat shock response, which are essential systems for environmental adaptation, such as nutrient limitation and proteotoxic stress. The Pho regulon and the heat shock response exemplify bacterial resilience, enabling rapid adaptation to fluctuating environmental conditions.Pho RegulonBacteria require phosphorus for essential cellular processes, including nucleic acid...
Negative Regulator Molecules01:23

Negative Regulator Molecules

Positive regulators allow a cell to advance through cell cycle checkpoints. Negative regulators have an equally important role as they terminate a cell’s progression through the cell cycle—or pause it—until the cell meets specific criteria.
The Extrinsic Apoptotic Pathway01:17

The Extrinsic Apoptotic Pathway

The extrinsic apoptotic pathway is initiated when extracellular death-inducing signals, such as specific cytokines, activate the death receptors expressed on the cell surface. The immune cells involved in this pathway are natural killer cells (NK cells) and cytotoxic T-lymphocytes. NK cells are critical in innate immune response, while cytotoxic T-lymphocytes are associated with adaptive immune response. These cells recognize specific receptors expressed on the altered cells and activate...