Fig. 4.
Copper inhibits LdtD from E. coli and Ldtfm from E. faecium. (A) PG sacculi from BW25113Δ6LDT were incubated with LdtD from E. coli. CuCl2 was added at different concentrations. Control samples contained no LdtD or no CuCl2. The numbers of the main muropeptides correspond to the structures shown in Fig. 2B. (B) The percentage of TetraTri(3–3) produced by LdtD was plotted against the concentration of CuCl2. The values are mean ± variation of two independent experiments. (C) E. faecium Ldtfm was incubated with nitrocefin (50 µM) in the presence of CuCl2 at a different concentration.