TABLE 2.

Relative kinetic parameters for wild-type and mutant TrpRS^a

Parameter	Wild type	Mutant	Mutant/wild-type
kcat,W	1.87	2.63	1.4
Km,W	0.092	0.073	0.79
kcat,W/Km,W	20.3	36.0	1.77
Km,4fW	49.70	205.23	4.1
r2	0.998	0.931

^aThe data in Fig. 9 were fitted to the equation used to calculate V_max,W by using nonlinear regresession. Since the data in Fig. 9 describe relative charging abilities, they do not allow the determination of absolute values for kinetic parameters.