Fig. 2. Site-specific incorporation of PABK into proteins by the Pyl-based genetic code expansion system in prokaryotic and eukaryotic systems. (A) Expression of GFP with an amber codon at Y40 and a C-terminal Flag tag in the presence and absence of 1 mM PABK with the help of PylRS-9/tRNACUA in HEK293T cells. (B) ESI-MS data for PABK incorporation into GFP at Y40 and GFP WT(Flag) as a reference. For GFP-Y40PABK(Flag): calculated 27 967 Da, found 27 969 Da; for GFP WT-Flag: calculated 27 827 Da, found 27 826 Da. (C) Expression of GFP with an amber codon at N150 and a C-terminal His tag with and without 1 mM PABK in the presence of PylRS-9/tRNACUA in E. coli.
