Ring-cleaving dioxygenase involved in the degradation pathway of the Pseudomonas aeruginosa quorum sensing signal molecules HHQ (2-heptyl-4-quinolone) and PQS (2-heptyl-3-hydroxy-4(1H)-quinolone) to anthranilate. Catalyzes the cleavage of PQS to form N-octanoylanthranilate and carbon monoxide. Thus, leads to the inactivation of PQS that plays a central role in the regulation of virulence factor production by P.aeruginosa, thereby quenching the production of antimicrobials, which may contribute to the competitiveness of M.abscessus in presence of P.aeruginosa (PubMed:31228546, PubMed:28303132). In vitro, can also use other 2-alkyl-3-hydroxy-4(1H)-quinolone (AHQ) substrates with shorter alkyl substituents at C2, but with lower efficiency (PubMed:31228546). 2-heptyl-3-hydroxy-4(1H)-quinolone + O2 = CO + H(+) + N-octanoylanthranilate kcat is 97.8 sec(-1) with 2-heptyl-3-hydroxy-4(1H)-quinolone as substrate (PubMed:28303132). kcat is 41.9 sec(-1) with 2-heptyl-3-hydroxy-4(1H)-quinolone as substrate. kcat is 18.3 sec(-1) with 2-butyl-3-hydroxy-4(1H)-quinolone as substrate. kcat is 1.63 sec(-1) with 2-methyl-3-hydroxy-4(1H)-quinolone as substrate (PubMed:31228546). Monomer. Up-regulated by PQS. Belongs to the AB hydrolase superfamily.