Table 2.

Kinetic parameters of WT and P-loop mutant dUTPases

Enzyme	Vmax (s-1)	KM (μM)	kcat/KM (M-1 s-1)	kH (s-1)	kdUTP,on (μM-1 s-1)	kdUTP,off (s-1)	kISO (s-1)
WT	6.5 ± 0.2	1.3 ± 0.5	5.0 × 106	5.5 ± 3 *	120 *	100 *	24 ± 6
hDUTR/K	0.078 ± 0.002	6.1 ± 1.7	1.3 × 104	0.048 ± 0.001	ND	ND	ND
hDUTST/AA	0.26 ± 0.1	12 ± 2	2.2 × 105	0.16 ± 0.01	84 ± 8	250 ± 40	29 ± 5
hDUTarmless	0.010 ± 0.0007	ND	7.1 × 103†	0.014 ± 0.0004	NA	NA	NA

^*data from Toth and coworkers (1)

^†K_d for the hDUT^armless.dUPNPP complex was used instead of K_M

ND: not determined

NA: not applicable