Table 1. Kinetic parameters of DmdNK and its mutant DmdNK-Q81E with different substrates.

	Substrate	KM (μM)	kcat (min-1)	kcat/KM (M-1 min-1)
DmdNK	dG	430.7±47.2	77.0 ±8.0	1.8 ×105
	dC	8.7±0.7	86.0 ±4.0	9.9×106
	dP	90.0 ±10.9	49.0 ±2.3	5.4 ×105
	dZ	101.7±4.0	0.35±0.02	3.5 × 103
DmdNK-Q81E	dG	1612.9±44	43.7±4	2.7 ×104
	dC	11.3±0.4	126±10	1.1 × 107
	dP	21.7±5.8	83.9±16.5	3.9 × 106
	dZ	0.68±0.15	4.0 ±0.8	5.9 × 106