Table 3.

Effect of modifications to the 3′-end on the kinetics of excision by ExoN. Data were fit either to a line (S > E) or to a single exponential (E > S) to determine observed rate of cleavage

	Rate (min−1)	Rate (min−1)
Modification	S > E	E > S
Unmodified	0.87 ± 01	2.2 ± 0.2
2′-fluoro	0.85 ± 0.3	1.7 ± 0.1
2′-O-methyl	0.64 ± 0.02	0.46 ± 0.04
2′-deoxy	0.41 ± 0.01	0.33 ± 0.02
2′-amino	0.33 ± 0.01	0.15 ± 0.02
3′-deoxy	0.035 ± 0.006	0.056 ± 0.008
3′-phosphate	No cleavage	No cleavage