Table 1.

Kinetic parameters of Tk-RNase HII mutants

Protein	Km (μM)	kcat
Wild type	0.093	1.0
D7A		<0.001
E8A	1.18	0.0015
D105A		<0.001
H132A	1.40	0.24
D135A	0.538	0.0020
Tk-RNase HII-217	0.0974	1.15
Tk-RNase HII-213	0.190	1.60
Tk-RNase HII-207	1.55	1.41
Tk-RNase HII-203	8.37	0.18
Tk-RNase HII198		<0.001

Errors, which represent 67% confidence limits, are all at or below ±20% of the values reported.