TABLE 2.

Extension from Gua:Cyt, Gua:Thy, and N²-ethyl-Gua:Cyt, N²-ethyl-Gua:Thy base pairs by DNA pol ι K_m and k_cat values were determined by quantifying gel band intensities using ImageQuant, and non-linear regression analysis of product versus [dNTP] curves, using SigmaPlot 8.0.2.

Metal ion	Base pair	Km	kcat	kcat/Km	Relative extension frequencya
		μm	min–1	min–1 μm–1
At template N2-ethyl-Gua
0.075 mm Mn2+
	N2-Et-Gua:Cytb	0.10 ± 0.012	210 ± 7	2.1 × 103	1
	N2-Et-Gua:Thy	0.30 ± 0.027	1.0 ± 0.02	3.3 × 100	1/640
2 mm Mg2+
	N2-Et-Gua:Cyt	40 ± 1	90 ± 4	2.3 × 100	1
	N2-Et-Gua:Thy	160 ± 40	0.31 ± 0.03	1.9 × 10–3	1/1180
At template Gua
0.075 mm Mn2+
	Gua:Cyt	0.25 ± 0.045	220 ± 10	8.8 × 102	1
	Gua:Thy	1.1 ± 0.09	1.3 ± 0.04	1.2 × 100	1/730
2 mm Mg2+
	Gua:Cyt	200 ± 30	110 ± 8	5.5 × 10–1	1
	Gua:Thy	170 ± 30	0.18 ± 0.013	1.1 × 10–3	1/500

^aRelative extension frequency is calculated as 1/([k_cat/K_m, correct]/[k_cat/K_m, incorrect])

^bEt, ethyl