FIG. 5.

Phosphorylation of N-acetylglucosamine by X. campestris pv. campestris NagK-II enzymes. (A) In vitro GlcNAc kinase assay based on the NAD⁺/NADH ratio of the wild-type strain (WT), strains with single deletions (ΔnagK-IIA and ΔnagK-IIB), or a strain with a double deletion (ΔnagK-IIAB) containing plasmid pC-nagK-IIA (pA), plasmid pC-nagK-IIB (pB), or no plasmid (−). The activity observed in ATP-depleted medium was subtracted to normalize the assay results. Strains were cultured in minimal medium supplemented with 10 mM N-acetylglucosamine (GlcNAc) to induce expression of the nagK-II genes. The error bars indicate the standard deviations obtained from 4 independent experiments. (B) Growth curves for mutant strains cultivated in minimal medium supplemented (+) or not supplemented (−) with GlcNAc. After overnight growth in complete medium, cells were harvested, washed, and resuspended in minimal medium containing 10 mM N-acetylglucosamine. The error bars indicate the standard deviations obtained from 4 independent experiments.