Chez Charles/ biblio/ Reactions at the termini of tRNA with T4 RNA ligase. Edit RecentChanges History Preferences Branchable Nucleic Acids Res. 1978 Oct;5(10):3665-77. Bruce AG, Uhlenbeck OC. Reactions at the termini of tRNA with T4 RNA ligase. Optimal temperature between 0 and 15 degrees. 15-20 % DMSO enhance the reaction. pCp is easily ligated to the 3' end of tRNAs, but the 5' end of tRNAs is difficult to ligate to pCp if it is engaged in a double helix.