The 3' ends of mature tRNAs prior to attachment of the amino acid are generated by:
◦ trimming of the precursor tRNA by exonuclease followed by addition of AAC.
◦ cleavage of precursor tRNA followed by exonuclease trimming and addition of AAC.
◦ trimming of the precursor tRNA by exonuclease followed by addition of CCA.
◦ cleavage of precursor tRNA followed by exonuclease trimming and addition of CCA.
◦ transcription termination.