In enzymology, a thyroid-hormone transaminase () is an enzyme that catalyzes the chemical reaction L-3,5,3'-triiodothyronine + 2-oxoglutarate 3-[4-(4-hydroxy-3-iodophenoxy)-3,5-diiodophenyl]-2-oxopropanoate + L-glutamate Thus, the two substrates of this enzyme are L-3,5,3'-triiodothyronine and 2-oxoglutarate, whereas its two products are [[3-[4-(4-hydroxy-3-iodophenoxy)-3,5-diiodophenyl]-2-oxopropanoate]] and L-glutamate. This enzyme belongs to the family of transferases, specifically the transaminases, which transfer nitrogenous groups. The systematic name of this enzyme class is L-3,5,3'-triiodothyronine:2-oxoglutarate aminotransferase. Other names in common use include 3,5-dinitrotyrosine transaminase, and thyroid hormone aminotransferase. It employs one cofactor, pyridoxal phosphate. References EC 2.6.1 Pyridoxal phosphate enzymes Enzymes of unknown structure