5-Thiohistidine N-Acetyltransferase from Proteiniphilum Saccharofermentans

Area of Science:

• Biochemistry
• Microbiology
• Enzymology

Background:

• Ovothiol A, a 5-thiohistidine derivative, is produced by various organisms and protects cells from oxidative stress.
• The enzymes responsible for ovothiol A biosynthesis are known, but enzymes for other 5-thiohistidine derivatives were uncharacterized.
• The structural and functional diversity of the 5-thiohistidine class was previously underestimated.

Purpose of the Study:

• To identify and characterize enzymes responsible for the biosynthesis of N-acetyl-5-thiohistidine.
• To investigate the diversity of 5-thiohistidine derivatives and their biosynthetic pathways.

Main Methods:

• Enzyme assays using acetyl-coenzyme A and histidine as substrates.
• Identification of novel transferase enzymes from bacterial species, including Proteiniphilum saccharofermentans.
• Biochemical characterization of the identified enzymes.

Main Results:

• A family of acetyl-coenzyme A-dependent transferases was identified.
• These enzymes were shown to produce N-acetyl-5-thiohistidine.
• The discovery was made in Proteiniphilum saccharofermentans and related Bacteroidota.

Conclusions:

• The 5-thiohistidine class of compounds is more structurally and functionally diverse than previously recognized.
• Novel biosynthetic pathways for 5-thiohistidine derivatives have been uncovered.
• This research opens new avenues for understanding cellular redox homeostasis and microbial metabolism.