Does not contain a metal centre or organic cofactor. Fission of two C-C bonds: 2,4-dioxygenolytic cleavage with concomitant release of carbon monoxide. The enzyme from Arthrobacter sp. can also act on 3-hydroxy-4-oxoquinoline, forming N-formylanthranilate and CO (cf. EC 220.127.116.11, 3-hydroxy-4-oxoquinoline 2,4-dioxygenase), but more slowly.