Table 1.

The galactokinase activity of Gal1p, Gal3p, and Gal3p+SA

Protein	Km (mM)		Turnover number (s−1)
	Galactose	ATP
Gal1p	0.25 ± 0.09	0.020 ± 0.003	20
Gal3p	ND	ND	0
Gal3p+SA	0.21 ± 0.06	0.17  ± 0.02	0.05

The galactokinase activity of each protein was measured by using an enzyme-linked assay described in Materials and Methods. Kinetic parameters were determined by using both double reciprocal and Hanes plots (22) and represent the average of at least four separate experiments. ND, no detectable activity.