TABLE 1.

Kinetic measurement of nucleotide incorporation by human Polι

dNTP	Vmax (fmol/min; mean ± SD)	Km (μM; mean ± SD)	Vmax/Km	finca
Template A
dATP	NDb	ND	0.0014	5.1 × 10−5
dGTP	3.4 ± 0.26	217 ± 45	0.016	5.9 × 10−4
dCTP	1.3 ± 0.26	592 ± 354	0.0022	8.1 × 10−5
dTTP	3.0 ± 0.05	0.11 ± 0.01	27.3
Template G
dATP	ND	ND	0.00094	6.7 × 10−4
dGTP	0.21 × 0.005	241 × 16	0.00087	6.2 × 10−4
dCTP	3.4 × 0.06	2.4 ± 0.17	1.4
dTTP	3.3 ± 0.31	118 ± 37	0.028	2.0 × 10−2
Template C
dATP	3.0 ± 0.11	141 ± 20	0.021	1.0 × 10−1
dGTP	3.2 ± 0.53	15.6 ± 5.6	0.21
dCTP	3.1 ± 0.18	162 ± 29	0.019	9.0 × 10−2
dTTP	3.3 ± 0.16	138 ± 22	0.024	1.1 × 10−1
Template T
dATP	3.5 ± 0.11	254 ± 22	0.014	1
dGTP	3.7 ± 0.14	24 ± 3.4	0.15	1.1 × 101
dCTP	0.76 ± 0.06	592 ± 142	0.0013	9.3 × 10−2
dTTP	3.6 ± 0.29	86 ± 25	0.042	3.0 × 100

^af_inc = (V_max/K_m)_incorrect/(V_max/K_m)_correct. 

^bND, not detected. The reaction velocity (v) remained linear throughout the entire dATP concentration range (0 to 1,000 μM). Therefore, individual V_max and K_m values could not be determined based on the plot of v versus [dATP]. The V_max/K_m value was determined by the slope of the initial velocity.