Reconstitution of the biochemical activities of the AttJ repressor and the AttK, AttL, and AttM catabolic enzymes of Agrobacterium tumefaciens

The attKLM operon encodes a lactonase (AttM) that hydrolyzes acylhomoserine lactone autoinducers, as well as two putative dehydrogenases (AttK and AttL). Here we show that AttK, AttL, and AttM collectively covert gamma-butyrolactone to succinate. Two metabolic intermediates, gamma-hydroxybutyrate and succinic semi-aldehyde, inactivated the AttJ repressor in vitro and induced attKLM transcription in vivo.