Tsa1 is the dominant peroxide scavenger and a source of HO-dependent GSSG production in yeast.

Hydrogen peroxide (HO) is an important biological molecule, functioning both as a second messenger in cell signaling and, especially at higher concentrations, as a cause of cell damage. Cells harbor multiple enzymes that have peroxide reducing activity in vitro. However, the contribution of each of these enzymes towards peroxide scavenging in vivo is less clear.