TABLE 3.

Catalytic properties of recombinant fumarases from B. xenovorans^a

Enzyme	Substrate	Vmax (U mg protein−1)	Km (mM)	kcat/Km (M−1 s−1)
Class I fumarase (Bxe_A3136)	Fumarate	296 ± 5	0.1 ± 0.01	2.8 × 106
	(S)-Malate	118 ± 3	0.28 ± 0.02	3.98 × 105
	Mesaconate	117 ± 6	0.03 ± 0.005	3.6 × 106
	(S)-Citramalate	74 ± 2	0.52 ± 0.05	1.31 × 105
Class II fumarase (Bxe_A1038)	Fumarate	376 ± 12	0.138 ± 0.013	2.2 × 106
	(S)-Malate	165 ± 6	0.42 ± 0.06	3.2 × 105
	Mesaconate	<0.1
	(S)-Citramalate	<0.1

^aValues are means ± standard deviation of results from at least three measurements.