Peptidsynthese im zellfreien System unter dem Einfluß von Hefe-Ribonucleinsäure

Total RNA from yeast stimulates the incorporation of 14C-amino acids into material insoluble in hot trichloroacetic acid in a cell-free E. coli system. In a sucrose gradient the stimulating RNA fraction sediments together with the 28 S fraction of ribosomal RNA. RNA from isolated yeast ribosomes preincubated with RNase was active in amino acid incorporation as well.Preincubation of ribosomal RNA at 70° resulted in an increased incorporation activity of the RNA. However, attempts to separate an active messenger fraction from total RNA as well as from 28 S RNA by heating were unsuccessful. The presented data indicate that ribosomal RNA itself is active in cell-free amino acid incorporation.By hydrolysis of the incorporation products it could be shown that the 14C-amino acids used in the cell free system were incorporated into peptides. The bulk of the radioactive peptides had a molecular weight below 2000 as estimated by Sephadex gel filtration.