The three iodothyronine deiodinases catalyze the initiation (D1, D2) and termination (D3) of thyroid hormone effects in vertebrates. A recently conceived 3-dimensional model predicts that these enzymes share a similar structural organization and belong to the thioredoxin (TRX) fold superfamily. Their active center is a selenocysteine-containing pocket defined by the b1-a1-b2 motifs of the TRX fold and a domain that shares strong similarities with the active site of iduronidase, a member of the clan GH-A fold of glycoside hydrolases. While […]