title: Effect of polaymines on yeast cell-free protein synthesizing system. I. Influence of spermine and spermidine on aminoacyl-tRNA transfer reaction.
abstract: Spermine and spermidine added to a Saccharomyces cerevisiae cell-free protein synthesizing system increased phenylalanine polymerization reaction several-fold at suboptimal concentration of Mg2+ and approximately two-fold at optimal amounts of Mg2+. The addition of polyamines greatly stimulated the enzymatic and nonenzymatic binding of phenylalanyl-tRNA and N-acetylphenylalanyl-tRNA to ribosomes. The binding of the acetylated derivative was higher than phenylalanyl-tRNA, however, as it was shown the former was bound exclusively to the A site of the ribosome. Contrary to the binding process, the puromycin reaction was not stimulated by spermine added at a concentration which enhanced the polyphenylalanine synthesis. These results indicate that polyamines have not only a sparing effect on the Mg2+ requirement for yeast protein synthesis in vitro and suggest that one of the possible sites of polyamines action might be the binding of aminoacyl-tRNA to ribosomes.
mesh_terms: D002474:Cell-Free System; D005656:Fungal Proteins / Q000096:biosynthesis*; D008274:Magnesium / Q000494:pharmacology; D010649:Phenylalanine / Q000378:metabolism; D012343:RNA, Transfer / Q000378:metabolism*; D012270:Ribosomes / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000378:metabolism*; D013095:Spermidine / Q000494:pharmacology*; D013096:Spermine / Q000494:pharmacology*
chemical_list: D005656:Fungal Proteins; D013096:Spermine; D010649:Phenylalanine; D012343:RNA, Transfer; D008274:Magnesium; D013095:Spermidine