The Use of Nucleoside Phosphotransferase and (P) p-Nitrophenyl Phosphate in the Determination of the 5'-Linked Termini of Ribosomal RNA.

A method for the identification of the 5'-linked termini of ribosomal RNA is described. The method involves the phosphorylation of the nucleosides released from the 5'-linked termini after hydrolysis of the ribonucleic acid chain with alkali. The radioactive 5'-nucleotide derivatives are formed by a nucleoside phosphotransferase mediated phosphoryl transfer from ((32)P) p-nitrophenyl phosphate to the nucleosides. The sensitivity of the method allows the use of small amounts of ribosomal RNA.Phosphorylation of the terminal nucleosides released from unfractionated cauliflower ribosomal RNA yielded radioactive adenylic acid and uridylic acid primarily, with the amount of adenylic acid being approximately twice that of uridylic acid.