Required for the synthesis of an autoinducer molecule beta-hydroxybutyryl homoserine lactone, which binds to LuxN and thus acts in bioluminescence regulation. a fatty acyl-[ACP] + S-adenosyl-L-methionine = an N-acyl-L-homoserine lactone + H(+) + holo-[ACP] + S-methyl-5'-thioadenosine Belongs to the LuxM / VanM family.