Glutathione analogs in prokaryotes

Oxygen is essential for aerobic life but also generates harmful reactive oxygen species. Thiols like cysteine are vulnerable to oxidative damage. Low-molecular-weight thiols serve protective roles in eukaryotes, with glutathione being the primary example. However, prokaryotes exhibit a more complex and diverse array of protective thiols. Prior research has shown that thiols buffer against ROS toxicity. The role of glutathione in bacteria is less understood. No prior work had resolved the full range of bacterial thiol systems. This gap motivated a comprehensive review of bacterial thiol diversity.

This review aims to explore the diversity of low-molecular-weight thiols in prokaryotes. The authors focus on how bacteria manage oxidative stress through various thiol systems. They highlight the limitations of cysteine as a protector. The study also investigates the origins and distribution of glutathione biosynthesis. Bacillithiol and mycothiol are examined as specialized bacterial thiols. Ergothioneine biosynthesis is another key topic. The review also considers coenzyme A and other protective thiols. Understanding these systems may inform antibacterial strategies.

The authors synthesized findings from existing literature on bacterial thiols. They reviewed the biochemical roles of cysteine and its limitations. The study analyzed the distribution of glutathione biosynthesis across prokaryotes. Mycothiol biosynthesis in Actinobacteria was examined in detail. Bacillithiol in Firmicutes was another focus. Ergothioneine’s biosynthesis and function were reviewed. The protective roles of coenzyme A and other thiols were also assessed. The review approach combined comparative analysis and functional insights.

Bacteria utilize multiple low-molecular-weight thiols to manage oxidative stress. Glutathione is present in some prokaryotes but not universally. Mycothiol is a key thiol in Actinobacteria. Bacillithiol is found in Firmicutes and offers protection. Ergothioneine biosynthesis is newly understood in bacteria. Coenzyme A and other thiols also contribute to protection. The diversity of thiols predates the oxygen-rich atmosphere. Pathogenic bacteria rely on unique thiol systems for survival.

The review highlights the diversity of bacterial thiol systems. These systems evolved to manage oxygen toxicity and environmental stress. Mycothiol, bacillithiol, and ergothioneine are examples of specialized thiols. The biosynthesis of these thiols is still poorly understood. Glutathione is not the sole protective thiol in prokaryotes. Some bacteria use alternative thiols for protection. The authors propose that these systems may serve as antibacterial targets. Further research is needed to clarify biosynthetic pathways.