DNA Backbone Sulfur-Modification Expands Microbial Growth Range under Multiple Stresses by its anti-oxidation...

Area of Science:

• Biochemistry
• Microbiology
• Genetics

Background:

• DNA phosphorothioate (PT) modification, a sulfur modification on the DNA backbone, is widespread in bacteria, including pathogens.
• Its physiological function, evolutionary significance, and application potential are largely unknown.

Purpose of the Study:

• To investigate the advantages of DNA PT modification for bacterial survival under environmental stress.
• To elucidate the protective mechanisms and evolutionary origins of DNA PT modification.

Main Methods:

• Comparative growth studies of modified and unmodified bacteria (Escherichia coli, Shewanella piezotolerans) under various stress conditions (temperature, salinity, pH, pressure, UV, X-ray, heavy metals).
• In vivo assessment of DNA protection against oxidative damage (H2O2, hydroxyl radicals).
• Analysis of the evolutionary divergence from DNA restriction-modification systems.

Main Results:

• DNA PT modification expanded the growth range of both mesophilic and extremophilic bacteria under diverse environmental stresses.
• Phosphorothioated DNA demonstrated in vivo reactivity to reactive oxygen species, protecting genomic DNA and enzymes from oxidative damage.
• Evidence suggests DNA PT modification evolved independently of DNA restriction and modification systems.

Conclusions:

• DNA PT modification confers significant physiological advantages to bacteria facing environmental challenges, particularly oxidative stress.
• This widespread modification has a crucial role in bacterial adaptation and survival.
• Findings suggest potential applications for DNA PT modification in biotechnology and biomedicine.