Table 5. Vent(exo-) Kinetics.

	KM (μM)	kcat (s–1)	kcat/KM (s–1 μM–1)	ratea
dCTP	5.42 (1.55)	0.48 (0.22)	0.089	1.00
dCmTP	2.98 (0.90)	0.61 (0.19)	0.206	2.33
dChmTP	7.67 (2.55)	0.65 (0.20)	0.084	0.95
dCfTPb	-	-	-	-
dTTP	3.95 (1.20)	0.59 (0.21)	0.149	1.00
dUhmTP	9.60 (2.74)	0.56 (0.08)	0.058	0.39
dUfTP	5.94 (1.01)	0.89 (0.12)	0.150	1.01

^aThe rate is defined as (k_cat/K_M)_modified/(k_cat/K_M)_natural.

^bNot performed since this polymerase die not give PEX products with dC^fTP. All experiments were performed in triplicate.