Ovoselenol, a Selenium-containing Antioxidant Derived from Convergent Evolution.

Area of Science:

• Biochemistry
• Metabolomics
• Enzymology

Background:

• Selenium is an essential micronutrient, primarily found in proteins and nucleic acids.
• The discovery of the first selenium-containing small molecule biosynthetic pathway indicates a broader, unexplored family of selenometabolites.
• The microbial selenometabolome remains largely uncharacterized.

Approach:

• Employed a bioinformatic search strategy using composite active site motifs to identify novel metalloenzymes.
• Conducted biochemical studies to validate the predicted function of these enzymes.
• Investigated the mechanism of C-Se bond formation in selenometabolite biosynthesis.

Key Points:

• Identified a newly evolved, abundant class of uncharacterized metalloenzymes potentially involved in selenometabolite biosynthesis.
• Biochemical validation confirmed these enzymes catalyze the formation of a novel C-Se bond on histidine.
• Characterized a new selenometabolite, ovoselenol, demonstrating potent antioxidant properties.

Conclusions:

• Elucidated the biosynthesis of a novel selenometabolite, ovoselenol, and its associated enzyme class.
• Provided insights into the evolution of metalloenzymes and the structural basis of C-Se bond formation.
• Established a framework for future exploration and mapping of the microbial selenometabolome.