Mechanism of action of S-ribosylhomocysteinase (LuxS)

S-Ribosylhomocysteinase (LuxS) cleaves the thioether bond in S-ribosylhomocysteine to produce homocysteine and 4,5-dihydroxy-2,3-pentanedione. This reaction serves the dual purposes of detoxification of S-adenosylhomocysteine and production of type 2 quorum sensing molecule. Recent research has shown that LuxS uses Fe(2+) to catalyze an internal redox reaction, shifting the ribose carbonyl group from its C1 to C3 position. Subsequent beta-elimination completes this highly unusual reaction. LuxS and other enzymes on the same pathway may provide a novel class of antibacterial drug targets.