'Total RNA' from Euglena gracilis was fractionated using a saline-extraction technique to isolate a 13-14-S DNA-RNA complex and two RNA fractions with sedimentation values of 15 S and 26 S. All the three fractions were labeled with 32Pi in 30-40 min and were highly active in stimulating amino acid incorporation in a cell-free Escherichia coli system. It was thus inferred that all these three fractions are messenger RNAs. The three messenger fractions possessed different base composition and incorporated the individual amino acids at varied proportions. The in vitro peptides synthesized by the three messenger fractions were also different with respect to their molecular weights and isoelectric points. The DNA-RNA complex made three peptides (all acidic) while the 26-S RNA made four peptides (all acidic). The 15-S RNA made five peptides of which three were basic and two were acidic. It is concluded that the three fractions are different messenger RNAs coding for different proteins.
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