Required for the synthesis of autoinducer molecules such as OHHL (N-(3-oxohexanoyl)-L-homoserine lactone), and HHL (N-hexanoyl-L-homoserine lactone). a fatty acyl-[ACP] + S-adenosyl-L-methionine = an N-acyl-L-homoserine lactone + H(+) + holo-[ACP] + S-methyl-5'-thioadenosine Belongs to the autoinducer synthase family.