Table 1.

Kinetic constants of wild-type DhaK and His56^K mutants for Dha substrate

	WT	H56AK	H56NK
(min-1)	507 ± 25	96.1 ± 2.0	223 ± 4.3
(mM)	< 0.008*	0.302 ± 0.005	2.20 ± 0.15
(mM-1 min-1)	> 6.3 × 104	318	101

Standard deviations were calculated from three independent experiments.

^*Due to the limited sensitivity of the glycerol-3-phosphate dehydrogenase coupled assay for WT at low substrate concentrations the could not be accurately determined.