Fig. 4
SrtA transpeptidase cleaving the LPXTG motifs linking penta-glycine from lipid II to the cleaved THR, containing 8-stranded β-barrel structure holding the catalytic pocket. Quaternary ammonium compounds or K21 is based on 1-octadecanaminium, N, N′-[[3,3-bis[[[3-(dimethyloctadecylammonio) propyl] dihydroxysilyl] oxy]-1,1,5,5-tetrahydroxy-1,5-trisiloxanediyl] di-3,1-propanediyl] bis [N, N-dimethyl-], chloride1:4 (C92H204Cl4N4O12Si5, using tetraethoxysilane and3-(triethoxysilyl)-propyl dimethyl octadecyl ammonium chloride