The function of KYAT3 (kynurenine aminotransferase 3, Ensembl gene identifier ENSG00000137944) is as follows. Catalyzes the irreversible transamination of the L-tryptophan metabolite L-kynurenine to form kynurenic acid (KA), an intermediate in the tryptophan catabolic pathway which is also a broad spectrum antagonist of the three ionotropic excitatory amino acid receptors among others. May catalyze the beta-elimination of S-conjugates and Se- conjugates of L-(seleno)cysteine, resulting in the cleavage of the C-S or C-Se bond. Has transaminase activity towards L-kynurenine, tryptophan, phenylalanine, serine, cysteine, methionine, histidine, glutamine and asparagine with glyoxylate as an amino group acceptor (in vitro). Has lower activity with 2-oxoglutarate as amino group acceptor (in vitro). .