2HZP, 3E9K894270789ENSG00000115919ENSMUSG00000026866Q16719Q9CXF0NM_001032998NM_001199241NM_003937NM_027552NM_001289593NM_001289594NM_001398676NP_001028170NP_001186170NP_003928NP_001276522NP_001276523NP_081828NP_001385605Kynureninase or L-Kynurenine hydrolase (KYNU) (EC 3.7.1.3) is a PLP dependent enzyme that catalyses the cleavage of kynurenine (Kyn) into anthranilic acid (Ant).

Humans express one kynureninase enzyme that is encoded by the KYNU gene located on chromosome 2.

To date, two structures of human kynureninase have determined by X-ray diffraction with resolutions of 2.0 and 1.7 Å.

The proposed reaction mechanism involves an attack of an enzyme nucleophile on the carbonyl carbon (Cγ) of the tautomerized 3hKyn-PLP Schiff base.

This is followed by Cβ-Cγ bond cleavage to generate an acyl-enzyme intermediate together with a tautomerized Ala-PLP adduct.