Table 3. Steady-State Kinetic Parameters for dNTP Incorporation Opposite 8-oxoG by Wild-Type and Variant hPols ι(1-445) in the Presence of 5 mM Mg²⁺.

pol ι(1–445)	dNTP	Km (μM)	kcat (s–1)	kcat/Km (s–1 mM–1)	finsa	relative efficiencyb
wild-type	A	1300 ± 200	0.00081 ± 0.00005	0.00062	0.077
	T	1600 ± 300	0.0027 ± 0.0002	0.0017	0.27
	G	230 ± 40	0.0032 ± 0.0001	0.014	1.7
	C	1600 ± 300	0.013 ± 0.001	0.0081	1	1
Δ1–25	A	530 ± 80	0.0034 ± 0.00017	0.0064	0.13
	T	510 ± 70	0.0074 ± 0.0003	0.015	0.31
	G	120 ± 10	0.0061 ± 0.00014	0.051	1.1
	C	1200 ± 100	0.057 ± 0.002	0.048	1	5.9
ΔD17	A	1000 ± 200	0.00088 ± 0.00005	0.00088	0.14
	T	2400 ± 200	0.0046 ± 0.0001	0.0019	0.30
	G	530 ± 50	0.0062 ± 0.0002	0.012	1.9
	C	4000 ± 900	0.025 ± 0.003	0.0063	1	0.78
R96G	A	840 ± 30c	0.000072 ± 0.000008	0.000086	0.36
	T	290 ± 70	0.00018 ± 0.00001	0.00062	2.6
	G	160 ± 20c	0.00010 ± 0.000003	0.00063	2.6
	C	1900 ± 400	0.00045 ± 0.00004	0.00024	1	0.030
I261M	A	820 ± 110	0.00075 ± 0.00003	0.00092	0.21
	T	1400 ± 300	0.0028 ± 0.0002	0.0020	0.47
	G	320 ± 20	0.0044 ± 0.0001	0.014	3.3
	C	2100 ± 300	0.0090 ± 0.0005	0.0043	1	0.53
E276K	A	1500 ± 100	0.0010 ± 0.00002	0.00066	0.11
	T	2200 ± 200	0.0055 ± 0.0002	0.0025	0.43
	G	920 ± 30	0.012 ± 0.0001	0.013	2.2
	C	3800 ± 200	0.022 ± 0.001	0.0058	1	0.72
Y374N	A	1000 ± 100	0.00061 ± 0.00003	0.00061	0.086
	T	1200 ± 200	0.0023 ± 0.0001	0.0019	0.27
	G	260 ± 20	0.0030 ± 0.0001	0.013	1.8
	C	1700 ± 800	0.012 ± 0.002	0.0071	1	0.88

^aMisinsertion frequency, calculated by dividing k_cat/K_m for dNTP incorporation by the k_cat/K_m for dCTP incorporation opposite 8-oxoG. All values are presented to two significant digits.

^bRelative efficiency, calculated by dividing k_cat/K_m of each pol ι(1–445) for dCTP incorporation opposite 8-oxoG by k_cat/K_m of wild-type pol ι(1–445) for dCTP incorporation opposite 8-oxoG.

^cThe apparent K_m value, determined under the condition where the amount of enzyme is greater than the amount of DNA and thus is not strictly steady-state.