Participation of GCCase and MCCase in the acyclic monoterpene and leucine catabolic pathways of P. aeruginosa PAO1 (1, 10). AtuD, citronellyl-CoA dehydrogenase; AtuC/AtuF, GCCase; AtuE, isohexenylglutaconyl-CoA hydratase; LiuA, isovaleryl-CoA dehydrogenase; LiuB/LiuD, MCCase; LiuC, 3-methylglutaconyl-CoA hydratase; LiuE, 3-hydroxy-3-methyl-glutaryl-CoA (also proposed as 3-hydroxy-3-isohexenylglutaryl-CoA lyase).