Role of the 5'-terminal phosphate of tRNA for its function during protein biosynthesis elongation cycle.

The 5'-terminal phosphate of tRNAPhe from yeast was removed using tRNAPhe lacking its 3'-terminal adenosine. After regeneration of the C-C-A terminus this tRNA was investigated in following reactions: aminoacylation, spontaneous hydrolysis of the amino acid from aminoacyl-tRNA, aminoacyl-tRNA.EF-Tu.GTP ternary complex formation and poly(U)-dependent synthesis of poly(Phe). The absence of the 5'-terminal phosphate of Phe-tRNAPhe does not influence the rate of hydrolysis of the amino acid or the ability of this rRNA to participate in complex formation with EF-Tu.GTP. The translation of the polyuridylic acid is slightly inhibited whereas the rate and extent of the enzymatic aminoacylation is not affected.