Table 2.

Pre-steady-state kinetic parameters for insertion of dNMPs by wild type RB69pol and its Y567A mutant.

Enzyme	dNTP	Template	kpol (s−1)	Kd,app (µM)	kpol/ Kd,app (µM−1 s−1)
Wild Type	dCTP	8-oxoG	55	97	0.57
	dATP	8-oxoG	1.7	1500	1.1 × 10−3
L561A	dCTP	8-oxoG	76	11	6.9
	dATP	8-oxoG	9.5	980	9.7 × 10−3
Y567A	dCTP	8-oxoG	91	29	3.1
	dATP	8-oxoG	110	48	2.3
	dGTP	A	0.015	250	6.0 × 10−5a
	dITP	A	~ 0.50	~ 1000	5.0 × 10−4b
	dGTP	dAP	~ 0.15	~ 200	8.0 × 10−4b
	dITP	dAP	NDc	NDc	3.0 × 10−5d

^aData obtained previously (33).

^bValues are estimates because the k_obs values decreased with increasing [dNTP]. K_d,app and k_pol values in these cases were obtained by fitting k_obs versus [dNTP] to Equation 2.

^cND = Not Determined because the value of K_d,app was too high (> 2 mM).

^dThe k_pol/K_d,app second order value was obtained in this case by calculating the slope of a linear line fitted to the data: y = mx + b, where m = slope = Δ k_obs/Δ[dNTP] = k_pol/K_d,app. Of the values shown, standard deviations were within 10–20% and ~30% for k_pol and K_d,app values, respectively.