A. HPLC-based PG digestion assay representing EPase activity. The graph shows the relative percentage of the muropeptide TetraTetra present at the end of the incubation period for each protein as described in materials and methods. MepM and PBP4 were incubated with sacculi, whilst MepS and PBP7 were incubated with soluble muropeptides, both from E. coli MC1061, respectively. Values are mean ± standard deviation of three independent experiments. To calculate significance, the data were fit using a linear model. Calculated means were compared using Tukey's HSD test, resulting in p-values corrected for multiple testing. Relevant p-values are highlighted directly in the figure (*<0.05; **<0.01, ***<0.001) 