. Author manuscript; available in PMC: 2014 Nov 5.

Published in final edited form as: Structure. 2013 Oct 3;21(11):10.1016/j.str.2013.08.021. doi: 10.1016/j.str.2013.08.021

Table 1B.

Kinetic parameters for tRNA^Ser of human wild-type and mutant SerRS proteins.

Enzyme	K_m (μM)^a	k_cat (s⁻¹)^a	Relative k_cat/K_m ^a	Kd (μM)^b
WT	0.77±0.25	0.43±0.040	1	0.37±0.010
ΔG254-N261	0.51±0.23	0.20±0.025	0.72	0.24±0.028
ΔG75-N97	0.33±0.40	0.025±0.004	0.13	0.19±0.016
ΔG75-N97ΔG254-N261	0.13±0.10	0.005±0.001	0.07	0.099±0.019

Determined by aminoacylation assay.

Determined by nitrocellulose filter binding assay.