Figure 1.

Simple aminobenzoic acid cyanomethyl esters are poor substrates for the eFx ribozyme. (A) Protocol used to detect acylation of microhelix (MH) or tRNA by cyanomethyl esters 1–3. (B) Acid-urea gel-shift analysis of MH acylation by cyanomethyl esters 1–3 in the presence of ribozyme eFx. Yield was estimated by UV densitometry. (C) LC-HRMS analysis of MH acylation reactions after RNase A digestion. Adenine nucleosides acylated on the 2′ or 3′ hydroxyl of the 3′ terminal ribose of MH could be detected in eFx-promoted reactions of the cyanomethyl ester of l-phenylalanine (Phe) and aminobenzoic acid esters 1 and 2; trace levels were detected in reactions containing 3. These products were not observed in analogous reactions containing m-aminobenzoic acid (compound C).