Synthesis of 5' Fragments of Formylmethionine Transfer Ribonucleic Acid and Their Reconstitution with a Natural Three-Quarter Molecule.

An eicosanucleotide C-G-C-G-G-G-G-U-G-G-A-G-C-A-G-C-C-U-G-Gp corresponding to the bases 1–20 of the nascent sequence for the Escherichia coli tRNA_f^Met has been synthesized by the joining of the chemically synthesized oligonucleotides C-G-C-G, G-G-G-U-G-G and A-G-C-A-G-C-C-U-G-Gp using RNA ligase from T4-infected E. coli. The hexanucleotide and decanucleotide were phosphorylated with polynucleotide kinase and [γ-³²p] ATP prior to the joining reactions. The decanucleotide and eicosanucleotide were reconstituted respectively with the 3′-three-quarter molecule obtained by limited digestion with RNase T1 of the natural tRNA_f^Met from E. coli and the activity of the complex as a methionine acceptor was tested using purified methionyl-tRNA synthetase from E. coli. The amino acid acceptor activity of the reconstituted molecules was 11% and 84% with respect to that of the intact tRNA_f^Met. [ABSTRACT FROM AUTHOR]