Thioredoxin reductases (TR, TrxR) (EC1.8.1.9) are enzymes that reduce thioredoxin (Trx).[1] Two classes of thioredoxin reductase have been identified: one class in bacteria and some eukaryotes and one in animals. In bacteria TrxR also catalyzes the reduction of glutaredoxin like proteins known as NrdH.[2][3][4] Both classes are flavoproteins which function as homodimers. Each monomer contains a FAD prosthetic group, a NADPH binding domain, and an active site containing a redox-active disulfide bond.[5]
^Phulera S, Mande SC (June 2013). "The crystal structure of Mycobacterium tuberculosis NrdH at 0.87 Å suggests a possible mode of its activity". Biochemistry. 52 (23): 4056–65. doi:10.1021/bi400191z. PMID23675692.