Table 3.

Kinetics of acyl-HSL synthesis by RhlI

Substrate	Km (μM)	Vmax (mol of products⋅min−1⋅mol−1 RhlI)
SAM	14	16
butyryl-ACP	6	16
butyryl-CoA	230	2
hexanoyl-ACP	8	10
octanoyl-ACP	43	2
butyryl-SAM	38	2

Kinetic constants were calculated with the appropriate FORTRAN programs (35). SAM was tested over a range of 4–95 μM at a butyryl-ACP concentration of 60 μM with 72 ng of RhlI. For the fatty acyl substrates, the SAM concentration was 95 μM. Butyryl-ACP was tested over a range of 4–60 μM with 72 ng of RhlI, hexanoyl-ACP over a range of 8.6–690 μM with 144 ng of RhlI, octanoyl-ACP over a range of 4.4–264 μM with 1.4 μg of RhlI, and butyryl-CoA over a concentration range of 28–780 μM with 3.6 μg of RhlI. Butyryl-SAM was tested over a concentration range of 10 μM–1 mM with 72 ng of RhlI. For SAM and butyryl-ACP, true K_m values are given; for the other substrates, apparent K_m values are indicated.