Table 1.

Steady-state kinetic analysis of AtGH3.15

Assays were performed with varied concentrations of one substrate and constant concentrations of the other two substrates. Fixed concentrations were as follows: IBA and JA (10 mm), ATP (1 mm), and Gln (25 mm). Initial velocity data were fit to the Michaelis–Menten equation using SigmaPlot. Average values ± S.D. (n = 3) are shown for steady-state kinetic parameters.

Varied substrate	Fixed substrates	kcat	Km	kcat/Km
		min−1	μm	m−1 s−1
IBA	Gln, ATP	9.9 ± 0.2	527 ± 43	313
JA	Gln, ATP	4.4 ± 0.1	1,120 ± 72	65
Gln	IBA, ATP	17.0 ± 0.7	1,780 ± 190	159
Gln	JA, ATP	4.0 ± 0.1	2,530 ± 160	26
Cys	IBA, ATP	16.0 ± 0.3	2,080 ± 190	128
His	IBA, ATP	21.0 ± 0.4	12,300 ± 640	28
Met	IBA, ATP	13.0 ± 0.5	5,670 ± 650	38
Tyr	IBA, ATP	25.0 ± 0.6	18,600 ± 3,050	22
ATP	IBA, Gln	13.0 ± 0.5	84 ± 12	2,580