a tRNA precursor + 2 CTP => a tRNA with a 3' CC end + 2 diphosphate
a trna precursor + 2 ctp => a trna with a 3' cc end + 2 diphosphate
a tRNA precursor + 2 CTP => a tRNA with a 3' CC end + 2 diphosphate
a trna precursor + 2 ctp => a trna with a 3' cc end + 2 diphosphate