Properties of phenylalanine transfer ribonucleic acid with modified 3′-terminal end in protein biosynthesis using a rabbit reticulocyte cell-free system: effect of the replacement of cytidine residues from the CpCpA end of tRNA by 5-iodocytidine or 2-thiocytidine
Keshet (Baksht), Eli; Gal, Alma; Groot, Nathan de; Hochberg, Abraham A.; Sprinzl, Mathias; Cramer, Friedrich; Department of Biological Chemistry, The Hebrew University of JerusalemIsrael; Sprinzl Mathias; Abteilung Chemie, Max-Planck-Institut für experimentelle Medizin; Cramer Friedrich; Abteilung Chemie, Max-Planck-Institut für experimentelle Medizin
Журнал:
Nucleic Acids Research
Дата:
1977
Аннотация:
Phe-tRNA<sup>phe</sup> from yeast containing 2-thiocytidine or 5-iodocytidine in position 75 of the polynucleotide chain or Phe-tRNA<sup>phe</sup> in which both positions 74 and 75 were substituted by 5-lodocytidine were investigated in the poly U-dependent polyphenylalanine synthesis on ribosomes from rabbit reticulocytes. Phe-tRNA<sup>phe</sup> Cps<sup>2</sup>CpA was nearly as active as the native Phe-tRNA<sup>phe</sup>-CpCpA in the overall process. Phe-tRNA<sup>Phe</sup>-Cpi<sup>5</sup>CpA as well as Phe-tRNA<sup>Phe</sup>-i<sup>5</sup>Cpi<sup>5</sup>CpA were considerably less active than the native species. In vestigation of individual steps of protein biosynthesis with these modified substrates revealed that the donor activity of peptidyl-tRNAs which contain 5-iodocytidine in their 3′-terminus is strongly impaired suggesting exacting structural requirements for the interaction of the C<sup>p</sup>C<sup>p</sup>A end of tRNA with the ribosomal P-site.
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