SepRS9/tRNA-SepA37 + EF-Sep21 (SepOTSλ) RS/tRNA Pair Development Year 2015 ncAA(s) Incorporated phosphoserine
AcKRS2 RS/tRNA Pair Development Year 2008 ncAA(s) Incorporated Nε-acetyl-L-lysine N6-Trifluoroacetyl-L-lysine