Table 1.

Kinetic parameters for Nudix hydrolase-catalyzed reactions

Nudix hydrolase	Substrate	Assay	pH	Phosphatase	kcat (s−1)	Km (μM)	kcat/Km (M−1 s−1)
MutT	8-Oxo-dGTP	F–S assay	7.6	PPase	6.9 ± 0.3	0.53 ± 0.09	(9.3 ± 1.1) × 106
			5.5a	0.26a	2.1 × 107a
Pi sensor	7.6	PPase	5.5 ± 0.1	0.28 ± 0.03	(8.9 ± 0.6) × 106
Pi sensor	7.6	None	0.89 ± 0.04	3.0 ± 0.4	(3.0 ± 0.2) × 105
8-Oxo-GTP	Pi sensor	7.6	PPase	11.2 ± 0.9	0.9 ± 0.2	(1.3 ± 0.2) × 107
5-Methyl-dCTP	Pi sensor	7.6	PPase	ND	ND	(2.8 ± 0.1) × 103
dCTP	Pi sensor	7.6	PPase	ND	ND	240 ± 200
NudD	GDP-mannose	Pi sensor	8.5	APase	ND	ND	(1.5 ± 0.1) × 103
F–S assay	8.5	APase	0.35 ± 0.02	220 ± 60	(1.6 ± 0.3) × 103
			0.63b	250b	2.5 × 103b
DR_1025	8-Oxo-dGTP	Pi sensor	7.6	None	0.18 ± 0.01	26 ± 1	(4.4 ± 0.1) × 103
F–S assay	7.6	None	0.29 ± 0.04	28 ± 7	(6.8 ± 0.8) × 103
8-Oxo-GTP	Pi sensor	7.6	None	0.13 ± 0.01	22 ± 5	(5.9 ± 0.8) × 103
dGTP	Pi sensor	7.6	PPase	ND	ND	860 ± 20
Pi sensor	7.6	None	ND	ND	950 ± 40
GTP	Pi sensor	7.6	None	ND	ND	820 ± 50
Ap4A	Pi sensor	7.6	APase	ND	ND	57 ± 6
Pi sensor	9.0	APase	ND	ND	110 ± 6
MM_0920	8-Oxo-dATP	Pi sensor	7.6	PPase	(9.6 ± 0.8) × 10−4	12 ± 3	78 ± 12
8-Oxo-dGTP	Pi sensor	7.6	PPase	(1.9 ± 0.2) × 10−3	13 ± 3	149 ± 25

Note. T = 37 °C except for data from Ref. [14], where T = 30 °C. F–S assay, Fiske–SubbaRow assay; ND, not determined because k_cat/K_m was obtained from linear regression fitting.

^aCalculated from data in Table 2 of Ref. [14].

^bCalculated from data in Fig. 2A of Ref. [26].