. 2005 Jan 26;33(2):536–545. doi: 10.1093/nar/gki196

Table 1.

Apparent kinetic constants for hydrolysis of ATP by UL9 during DNA translocation

DNA	k_cat (ATP) (min⁻¹)^a	K_m (ATP) (mM)^a	k_cat (DNA) (min⁻¹)^b	K_m (DNA) (nM)^b	V_max (UL9) (μM/min)^c	K_m (UL9) (nM)^c
38mer	n.d.^d	n.d.	407 ± 19	47 ± 9.7	17.8 ± 1.8	72.7 ± 14.7
23/38mer	360 ± 19	0.68 ± 0.11	460 ± 16	38.0 ± 5.9	25.0 ± 2.2	94.2 ± 14.9

^aA 50 nM fixed concentration of UL9 was incubated with excess (500 nM) DNA and increasing concentrations of ATP (0–5 mM). Observed ATP hydrolysis rate constants were plotted against ATP concentration and fit to the Michaelis–Menten function (Equation 2) to estimate apparent k_cat and K_m (±SD) for ATP as indicated in Materials and Methods.

^bA 50 nM fixed concentration of UL9 was incubated with increasing concentrations of DNA (0–1024 nM) in the presence of excess (3 mM) ATP. Apparent kinetic constants were obtained by fitting plots of ATP hydrolysis rate constants as a function of DNA concentration to the Michaelis–Menten function.

^cUL9 concentrations were varied (0–288 nM) and incubated with a fixed concentration of DNA (50 nM) and ATP (3 mM). Plots of ATP hydrolysis rates as a function of UL9 concentration were fit to the Hill equation (Equation 3) using a Hill coefficient of 2 to estimate the maximum rate at infinite UL9 concentration (V_max) and the apparent K_m for UL9 as indicated.

^dNot done (n.d.).