O2tase

O2tase is a proposed name for enzymes that activate molecular oxygen through metal or flavin cofactors to drive oxidative reactions. Depending on the enzyme, the reaction may insert one or more oxygen atoms into substrates, or reduce O2 to water as part of substrate oxidation or detoxification pathways.

Structural and mechanistic diversity is expected; non-heme iron and copper centers, heme-containing enzymes, and flavoproteins have all been observed in related oxygen-activating enzymes. In some organisms, O2tases may operate with electron donors such as NADH, NADPH, ferredoxin, or quinone pools.

Occurrence and discovery: The O2tase concept has emerged in discussions of unclassified oxidoreductases identified by genome and metagenome sequencing. It is not a formally codified enzyme family in all taxonomic schemes, and individual members may be classified under established categories such as oxidoreductases or monooxygenases as evidence clarifies their substrates.

Biological roles and applications: Potential roles include xenobiotic degradation, biosynthesis of hydroxylated metabolites, and signaling via reactive oxygen species. In biotechnology, engineered O2tases could enable selective hydroxylation or oxygenation of organic substrates under mild conditions, with implications for pharmaceutical synthesis and bioremediation.