TABLE 3.

Specific enzyme activities of PrpC1 and PrpC2 as citrate synthases and 2-methylcitrate synthases

Strain	Plasmid	Condition	Sp act [μmol (min mg)−1]a		MCS/CS ratiob
			Citrate synthase	2-Methylcitrate synthase
C. glutamicum GLTA1	pZ8-1		<0.01	<0.01
	pZ-prpC1		1.99 ± 0.15	0.84 ± 0.01	0.4
	pZ-prpC2		2.79 ± 0.23	5.93 ± 0.46	2.1
E. coli DH5α	pTrc99a	−IPTG	0.21 ± 0.01	<0.01
	pTrc99a	+IPTG	0.23 ± 0.01	<0.01
	pTrc-prpC1	−IPTG	0.32 ± 0.01	0.04 ± 0.01	0.4
	pTrc-prpC1	+IPTG	1.73 ± 0.09	0.70 ± 0.03	0.5
	pTrc-prpC2	−IPTG	0.43 ± 0.01	0.38 ± 0.04	1.7
	pTrc-prpC2	+IPTG	5.25 ± 0.17	10.42 ± 0.77	2.1

^aSpecific enzyme activities are given as means of at least three independent measurements ± standard deviation.

^bMCS/CS ratios were calculated after subtraction of the E. coli background citrate synthase activity.