preferred_name: a tRNA precursor + 2 CTP + ATP => a tRNA with a 3' CCA end + 3 diphosphate
preferred_name_lc: a trna precursor + 2 ctp + atp => a trna with a 3' cca end + 3 diphosphate
label: a tRNA precursor + 2 CTP + ATP => a tRNA with a 3' CCA end + 3 diphosphate
label_lc: a trna precursor + 2 ctp + atp => a trna with a 3' cca end + 3 diphosphate