Table 2.

Aminoacylation kinetics of NmLeuRSs at 40°C^a

tRNALeu	LeuRS	Km (μM)	kcat (s−1)	kcat/Km (mM−1 s−1)	Activity ratio
NmtRNALeu(GAG)	NmLeuRS1	7.73 ± 0.22	(6.40 ± 0.19) × 10−2	8.28	1b
	NmLeuRS2	3.35 ± 0.21	(6.68 ± 0.22) × 10−4	0.199	1/42
NmtRNALeu(CAA)	NmLeuRS1	11.01 ± 1.36	(4.64 ± 0.34) × 10−2	4.21	1/2
	NmLeuRS2	13.13 ± 1.57	(4.18 ± 0.50) × 10−4	0.0318	1/260
PhtRNALeu(GAG)	NmLeuRS1	12.51 ± 2.16	(4.18 ± 0.60) × 10−2	3.34	1/2.5
	NmLeuRS2	16.43 ± 0.62	(1.19 ± 0.08) × 10−3	0.0724	1/114

^aThe results are the average of three independent repeats with standard deviations indicated.

^bThe activity of NmLeuRS1 for NmtRNA^Leu(GAG) is defined as 1.