The CCA terminal of tRNA_(CA)~(Ala) , tRNA_(CG)~(Ala) and tRNA_(CC)~(Ala) was added through the nucleotidyltransferase present in the preparation of the tRNA aminoacyl synthetases in the presence of CTP and ATP.

• tRNA_(CA)~(Ala)、tRNA_(CG)~(Ala)和tRNA_(CC)~(Ala)首先被混合氨酰基tRNA合成酶制剂中的转核苷酸酶,在CTP和ATP存在的情况下,加上了CCA末端。