RNA. 2004 Apr;10(4):731-46. doi:10.1261/rna.5247704

Silverman SK.

Practical and general synthesis of 5'-adenylated RNA (5'-AppRNA).

The adenylation of RNA by T4 RNL1 is enhanced when they are annealed to a DNA oligos, leaving 3-4 protruding 5'ribonucleotides.