Table 3.

SFR1–SFR3 kinetic data

5′-TAATACGACTCACTATAGGGAGA

3′-ATTATGCTGAGTGATATCCCTCTXGCTAGGTTACGGCAGGATCGC

↓ dNTP or rNTP

5′-TAATACGACTCACTATAGGGAGAN

3′-ATTATGCTGAGTGATATCCCTCTXGCTAGGTTACGGCAGGATCGC

	X	Single incorporation of correct dNTP kcat/KM, min−1⋅M−1	Single incorporation of correct rNTPkcat/KM, min−1⋅M−1
SF	dT	2.77  × 105	8.3
	dG	4.42  × 106	1.2  × 103
	dC	3.03  × 106	1.5  × 103
	dA	8.5  × 105	8.0
SFR1	dT	6.1  × 104	1.4  × 105
	dG	2.8  × 105	7.0  × 105
	dC	2.4  × 105	6.7  × 105
	dA	1.5  × 105	1.0  × 105
SFR2	dT	3.1  × 104	7.9  × 104
	dG	2.5  × 105	5.7  × 105
	dC	1.7  × 105	3.8  × 105
	dA	1.0  × 105	5.9  × 104
SFR3	dT	4.6  × 104	1.4  × 105
	dG	5.0  × 105	1.3  × 106
	dC	6.7  × 105	1.3  × 106
	dA	1.6  × 105	9.7  × 104

Assay conditions: 40 nM template-primer, 0.11–1.34 nM SF, 20 mM Tris (pH 8.0), 10 mM MgCl₂, 1 mM DTT, 50 μg/mL BSA. Reactions were initiated by adding the DNA-SF mixture to an equal volume (5 μl) of a 2 × NTP stock solution, incubated at 50 °C, and quenched by the addition of 20 μl 95% formamide, 20 mM EDTA. The reaction mixture (5 μl) was analyzed by 15% PAGE containing 8 M urea. Data shown are the average of three independent determinations.