Figure 1.

Schematic depiction of the reported method for sortase-mediated tagging of the S. aureus cell wall. Bacteria are fed peptides containing small molecule tags. Upon penetrating the cell wall, these compounds are recognized by the periplasmic enzyme Sortase A (red dots), which cleaves between the C-terminal Thr and Gly residues and covalently attaches the remaining N-terminal portion to lipid II in the forming cell wall, as shown.