ROS Defense Systems and Terminal Oxidases in Bacteria

Reactive oxygen species (ROS) comprise the superoxide anion (O-2(center dot-)), hydrogen peroxide (H2O2), hydroxyl radical ((OH)-O-center dot), and singlet oxygen (O-1(2)). ROS can damage a variety of macromolecules, including DNA, RNA, proteins, and lipids, and compromise cell viability. To prevent or reduce ROS-induced oxidative stress, bacteria utilize different ROS defense mechanisms, of which ROS scavenging enzymes, such as superoxide dismutases, catalases, and peroxidases, are the best characterized. Recently, evidence has been accumulating that some of the terminal oxidases in bacterial respiratory chains may also play a protective role against ROS. The present review covers this role of terminal oxidases in light of recent findings.

Automated summary

Reactive oxygen species (ROS) can damage various macromolecules and compromise cell viability, prompting bacteria to utilize different defense mechanisms, such as ROS scavenging enzymes. Additionally, some terminal oxidases in bacterial respiratory chains may also play a protective role against ROS, as suggested by recent findings.