TABLE 2.

Kinetic parameters for native and point mutants of pgID

Kinetic values are apparent and were derived from the average of duplicate assays conducted at 37 °C in 20 mm HEPES, 150 mm NaCl, pH 7.1. Concentration of AcCoA was held at 2 mm, and the concentration of UDP-4-amino-sugar varied between 0.1 mm and 3 mm.

Construct	Protein	Km	kcat	kcat/Km	Vmax
	mg/assay	mm	s−1	s−1 mm−1	nmol/s/mg
Native	2.5 × 10−8	1.0 ± 0.1	314	314	1.47 × 104
H15A	5.0 × 10−7	2.5 ± 0.3	138	55	6.46 × 103
H125A	6.5 × 10−4	1.0 ± 0.2	9.1 × 10−2	9.1 × 10−2	4.25
H134A	2.0 × 10−6	0.8 ± 0.2	10	13	4.71 × 102