Table 3. Comparison of Reaction Rate Constants of DcpS-Mediated Cap Hydrolysis^a.

	N-tagged	nativeb	C-tagged
Human DcpS
m7GpppG	0.39 s–1 ± 0.05	0.37 s–1 ± 0.04	0.56 s–1 ± 0.03
			(1.5×)c
C. elegans DcpS
m7GpppG	1.13 s–1 ± 0.07	0.38 s–1 ± 0.04	1.49 s–1 ± 0.06
	(2.9×)		(3.9×)
m32,2,7GpppG	4.02 s–1 ± 0.18	2.34 s–1 ± 0.32	6.98 s–1 ± 0.56
	(1.7×)		(3.0×)
A. suum DcpS
m7GpppG	1.55 s–1 ± 0.01	1.85 s–1 ± 0.06	1.39 s–1 ± 0.06
	(0.80×)		(0.75×)
m32,2,7GpppG	1.84 s–1 ± 0.06	2.38 s–1 ± 0.06	2.12 s–1 ± 0.01
	(0.77×)		(0.89×)

^aDetermined reaction rate constants correspond to the arithmetic mean of three independent experiments (± SE).

^bNative forms of DcpS were obtained via N-terminal tag cleavage.

^cIn brackets, the relative ratio of reaction rate values of tagged to untagged DcpS is shown.