thioredoxin and glutathione reductase selenoprotein
This homodimeric, FAD-containing member of the pyridine nucleotide disulfide oxidoreductase family contains a C-terminal motif Cys-SeCys-Gly, where SeCys is selenocysteine encoded by TGA (in some sequence reports interpreted as a stop codon). In some members of this subfamily, Cys-SeCys-Gly is replaced by Cys-Cys-Gly. The reach of the selenium atom at the C-term arm of the protein is proposed to allow broad substrate specificity.
Jiyao W et al.(2023). "The conserved domain database in 2023.",