Extended Data Figure 3. Comparison of MccB/subtiligase-catalyzed and eSrtA-catalyzed C-terminal protein modification.

(A) MccB/subtiligase-catalyzed C-terminal peptide ligation to GS-GFP-TeCH. In the absence of peptide nucleophile, MccB and subtiligase catalyze GS-GFP cyclization, but this reaction is efficiently suppressed in the presence of 5 mM Ala-Phe. (B) eSrtA-catalyzed C-terminal modification of GS-GFP-LPETGG. In the absence of nucleophile, eSrtA catalyzes GFP cyclization that cannot be completely suppressed even in the presence of 10 mM GGG peptide. (C) eSrtA cyclization is suppressed by removing the N-terminal GS sequence at the N terminus of GS-GFP-LPETGG.