Use of nucleotide analogs by class I and class II CCA-adding enzymes (tRNA nucleotidyltransferase): Deciphering the basis for nucleotide selection

Addition of CTP analogs to tRNA-D. (A) Incorporation of CTP analogs zebularine, pseudoisocytidine, and 6-azacytidine into tRNA substrates lacking 3′-terminal CCA. The CTP control was carried out for only 3 min using low CTP (25 μM) to show the mobility of tRNA-DC as well as tRNA-DCC. (B) Incorporation of CTP analogs 5-fluorocytidine and 5-methycytidine into tRNA substrates lacking 3′-terminal CCA. Assays as in Figure 2B.