Catalyzes the irreversible transamination of the L-tryptophan metabolite L-kynurenine to form kynurenic acid (KA). 2-oxoglutarate + L-kynurenine = H2O + kynurenate + L-glutamate Amino-acid degradation; L-kynurenine degradation; kynurenate from L-kynurenine: step 1/2. Homodimer. Present with 1600 molecules/cell in log phase SD medium. Belongs to the class-I pyridoxal-phosphate-dependent aminotransferase family.