thioredoxin reductase 1 is a pyridine nucleotide oxidoreductase which reduces thioredoxins as well as other substrates, and plays a role in selenium metabolism and protection against oxidative stress. It is thought to function as a homodimer which uses FAD as a cofactor. Each subunit contains a selenocysteine residue which is required for the catalytic activity. Alternative splicing results in several transcript variants encoding the same protein. Additional transcript variants have been described but their biological validity has not been determined.
