The enzyme, characterized from the bacterium Pseudomonas aeruginosa, is a heterodimeric complex. The PqsC subunit acquires an octanoyl group from octanoyl-CoA and attaches it to an internal cysteine residue. Together with the PqsB subunit, the proteins catalyse the coupling of the octanoyl group with (2-aminobenzoyl)acetate, leading to decarboxylation and dehydration events that result in closure of the quinoline ring.
