Catalyzes the cleavage of L-kynurenine (L-Kyn) and L-3-hydroxykynurenine (L-3OHKyn) into anthranilic acid (AA) and 3-hydroxyanthranilic acid (3-OHAA), respectively. H2O + L-kynurenine = anthranilate + H(+) + L-alanine 3-hydroxy-L-kynurenine + H2O = 3-hydroxyanthranilate + H(+) + L-alanine Amino-acid degradation; L-kynurenine degradation; L-alanine and anthranilate from L-kynurenine: step 1/1. Cofactor biosynthesis; NAD(+) biosynthesis; quinolinate from L-kynurenine: step 2/3. Homodimer. Belongs to the kynureninase family.