Table 2.

GlcNAc-lipid synthesis in membrane fractions from various bacterial strains

Reaction mixtures contained 50 mm Tris-HCl, pH 7.4, 5 mm 2-mercaptoethanol, 20 mm MgCl₂, 1 mm ATP, 5 μm UDP-[³H]GlcNAc (486 cpm/pmol), and bacterial membrane suspension (50–100 μg of membrane protein) in a total volume of 0.01 ml. Following a 10-min preincubation at 30 °C, GlcNAc-lipid synthesis was initiated by the addition of UDP-[³H]GlcNAc. After 5 min, reactions were processed for GlcNAc-lipid synthesis as described under “Experimental procedures.” The results are representative of at least three separate experiments.

Enzyme source	GlcNAc-P-Und	GlcNAc-P-P-Und
	pmol/mg	pmol/mg
MGAS5005	259.4 ± 8.2	7.8 ± 1.8
5005ΔgacI	Not detected	15.9 ± 2.5
GBS COH1	62 ± 0.4	5.6 ± 0.8
GBSΔgacI	Not detected	12 ± 2
E. coli Rosetta (DE3)	Not detected	19.5 ± 0.3
E. coli:GacI	102.8 ± 3.3	5.4 ± 0.05
E. coli:EpaI	189 ± 3.9	7 ± 1.5