Table 1.

Kinetic parameters for wild type and ΔCP1 LeuRS mutants

Enzyme	Aminoacylation		Amino acid activation
	Km, μM	kcat, s−1	Km, mM		kcat, s−1
	Leu	Leu	Leu	Ile	Leu	Ile
ecLeuRS WT	0.7 ± 0.1	9.6 ± 2.7	0.018 ± 0.008	1.0 ± 0.3	71 ± 25	4.7 ± 1.3
ecLeuRSΔCP1	23.1 ± 3.6*	5.2 ± 1.3*	0.021 ± 0.006	3.4 ± 0.9	0.23 ± 0.07	2.2 ± 1.3
ymLeuRS WT	0.7 ± 0.12	5.06 ± 0.25	0.17 ± 0.08†	10.52 ± 0.92†	3.3 ± 0.6†	0.95 ± 0.2†
ymLeuRSΔCP1	19.9 ± 1.2*	1.05 ± 0.75*	38 ± 1.25*	‡	0.32 ± 0.02*	‡

*Apparent value.

^†Ref. 5.

^‡Not determined because of low activity.