FIG. 4.

The active site Cys residues of Trx3 are required to promote cell death. (A) Schematic of mitochondrial Trx3 showing the two redox active Cys residues (Cys55, Cys58) within the Cys-Gly-Pro-Cys motif that are conserved among thioredoxins from all species. Trx3 also contains two extra Cys residues (Cys80, Cys92), which are not present in cytoplasmic Trx1 and Trx2. (B) A glr1 trr2 trx3 mutant containing wild-type (TRX3) on a single copy vector (vector) or Cys mutant versions of TRX3 (C55S, C58S, C80S, C92S) were grown to an exponential phase and spotted onto fermentative synthetic dextrose (SD) or respiratory synthetic glycerol ethanol (SGE) media containing acetic acid. Growth was scored after 3 days. Cys, cysteine; SD, synthetic dextrose.