Required for the biosynthesis of the quorum-sensing signaling molecules 2-heptyl-4(1H)-quinolone (HHQ) and 2-heptyl-3-hydroxy-4(1H)-quinolone (Pseudomonas quinolone signal or PQS), which are important for biofilm formation and virulence. The PqsC/PqsB complex catalyzes the condensation of 2-aminobenzoylacetate (2-ABA) and octanoyl-CoA to form HHQ. First, PqsC acquires an octanoyl group from octanoyl-CoA and forms an octanoyl-PqsC intermediate. Then, together with PqsB, it catalyzes the coupling of 2-ABA with the octanoate group, leading to decarboxylation and dehydration, and resulting in closure of the quinoline ring. (2-aminobenzoyl)acetate + H(+) + octanoyl-CoA = 2-heptyl-4(1H)-quinolone + CO2 + CoA + H2O Folding of PqsC and binding of octanoate are promoted by PqsB (PubMed:24239007). Binding of the octanoyl group probably increases the binding affinity of the complex for 2-ABA (PubMed:26811339). Activity of the complex is inhibited by 2-aminoacetophenone (2-AA) (PubMed:26811339). kcat is 6.8 sec(-1). Forms a tight complex with PqsB. Belongs to the thiolase-like superfamily. FabH family.