TABLE 4.

Kinetic parameters for RacE1 and RacE2

Protein	l→d racemizationa			d→l racemizationa
	kcat (s−1)b	Km (mM)c	kcat/Km (103 M−1 s−1)d	kcat (s−1)e	Km (mM)f	kcat/Km (103 M−1 s−1)g
RacE1	12 ± 0.6	19 ± 4	0.64 ± 0.2	1.8 ± 0.1	1.0 ± 0.2	1.7 ± 0.2
RacE2	18 ± 0.6	38 ± 6	0.48 ± 0.2	2.0 ± 0.1	0.77 ± 0.1	2.6 ± 0.2

^aThe racemization of both d- and l-glutamate by RacE1 and RacE2 was analyzed as described in Materials and Methods. Each reaction was performed with three independent enzyme preparations, and the data are means ± standard deviations of the means. The kinetic parameters for RacE1 and RacE2 were assessed for statistically significant differences by the Student t test.

^bP = 0.0003.

^cP = 0.01.

^dP = 0.4.

^eP = 0.07.

^fP = 0.1.

^gP = 0.005.