Cytosolic tyrosine aminotransferase (TAT) catalyzes the reversible reaction of 3-(4-hydroxyphenyl)pyruvate and glutamate to form tyrosine and alpha-keto (2-oxo) glutarate (Mitchell et al. 2001). The enzymatic activity of the protein encoded by the cloned human TAT cDNA is inferred from the biochemical properties of its rat homologue. Unpublished crystallographic studies (PDB 3DYD) have shown TAT to be a homodimer with a pyridoxal phosphate moity attached to lysine-280 in each monomer.
L-tyrosine:2-oxoglutarate aminotransferase activity of TAT dimer [cytosol]