FIGURE 2.

Enzymatic assay of the V. cholerae Kdo transferase and Kdo kinase. A, E. coli NovaBlue (DE3) membranes containing either pET21 or WaaA plasmids from E. coli, H. influenzae, or V. cholerae were assayed for Kdo transferase activity at 0.001 mg/ml for 1 h at 30 °C with [4′-³²P]lipid IV_A substrate. The small amount Kdo₂-l4′-³²P]lipid IV_A in the vector control lane results from endogenous levels of E. coli WaaA. B, E. coli HMS174 (DE3) membranes expressing Vc0227 (0.1 mg/ml) were assayed for Kdo kinase activity using Kdo-[4′-³²P]lipid IV_A substrate in the presence or absence of ATP.