Table 1.

Initial rates of FabH or C112Q mutant reactivity with substrates and analogs^*

	FabH wt (rates in min−1)			FabH C112Q (rates in min−1)
reactants → products	pH 6	pH 7	pH 8	pH 6	pH 7	pH 8
acetyl- & malonyl-CoA → acetoacetyl-CoA	0.47 ± 0.04	0.74 ± 0.01	0.81 ± 0.01
malonyl-CoA → acetyl-CoA/acetoacetyl-CoA	n.d.	biphasic	0.043 ± 0.001‡	0.0060 ± 0.0006	0.18 ± 0.01	0.20 ± 0.02
acetyl-CoA → CoA	0.0004 ± 0.0001	0.0010 ± 0.0001	0.0038 ± 0.0002	0.0005 ± 0.0001	0.0006 ± 0.0001	0.0030 ± 0.0001
malonyl-CoA → CoA				0.0005 ± 0.0001	0.0007 ± 0.0001	0.0032 ± 0.0005
acetyl-oxa(dethia)CoA → oxa(dethia)CoA			~ 0.003			~ 0.001
malonyl-oxa(dethia)CoA → oxa(dethia)CoA			~ 0.001			~ 0.001

^*Reactions determined by HPLC analysis have ~250 μM substrate or analog and 10 μM FabH wt or FabH C112Q. Not detected (n.d.)

^‡Reaction contained 25 μM acetyl-CoA to alleviate lag phase, value is for acetoacetyl-CoA appearance, malonyl-CoA disappearance rate is approximately double.