Table 2. Enzyme kinetics for Hxk2 and Hxk2^G238V.

	Km Glucose (mM)	SA Glucose (nmole/min/au)	Km 2DG (mM)	SA 2DG (nmole/min/au)	Km ATP (mM)	SA ATP (nmole/min/au)
WT Hxk2	0.23 ± 0.02	27.6 ± 1.6	0.48 ± 0.06	8.59 ± 0.67	0.13 ± 0.01	24.2 ± 1.0
Hxk2 G238V	2.3 ± 0.37 (***)	8.9 ± 1.0 (**)	ND	ND	2.0 ± 0.21 (***)	7.1 ± 0.71 (**)

Each value is the mean of three experimental replicates ± the standard deviation. The raw data to support these measurements is presented in Fig B in S1 Text. Statistical analyses using a Student’s t-test to compare WT Hxk2 values to those of Hxk2^G238V are provided in parenthesis, where a p-value of ns = not significant

* < 0.05

** < 0.005, and

*** < 0.0005. The enzymatic activity of Hxk2^G238V against 2DG was not easily detectible above the background levels, so measurements were not determined (ND). However, Hxk2^G238V can clearly catalyze the conversion of 2DG because this allele elevates the sensitivity of galactose-grown cells to 2DG (see Fig 5D). K_m represents the Michaelis-Menten constant, and SA represents the specific activity (V_max normalized by the enzyme level).