Prcflavine, in the range of 5 x 1OU5 M, markedly inhibited prctein synthesis in a subcellular rat liver system. With native messenger ribonucleic acids, leucine incorporation was inhibited more than phenylalanine incorporation. In the presence of polyuridylate, however, phenylalanine incorporation was inhibited more than leucine incorporation. Reversal studies indicated that excess transfer rib...

Martin, Malec, Sved & Work (1961 b) showed that, during a single growth cycle, infection with encephalomyocarditis virus caused no changes in the total deoxyribonucleic acid, ribonucleic acid or protein of the host ascites-tumour cell. However, by the use of [6-14C]orotic acid and [14C]valine, it was shown that there were substantial changes in the rates of turnover of ribonucleic acid andprote...

The ratios of ribonucleic acid to protein contents of Clostridium botulinum type C, D, and E cultures were lower than those of type A, B, and F cultures. Addition of ribonucleic acid at 0.4 mg/ml to culture satisfactorily aided acid precipitation of type C and D toxins, but not that of type E toxin.

A mutant of Escherichia coli that lacks leucyl-, phenylalanyl-transfer ribonucleic acid-protein transferase had diminished activities of L-phenylalanyl-transfer ribonucleic acid synthetase and tryptophanase, grew faster than its parent with aspartic acid as the sole nitrogen source, accumulated higher levels of enterochelin in the medium during iron limitation, and exhibited an abnormal morphol...

An increase in the rate of synthesis of ara-specific messenger ribonucleic acid as measured by deoxyribonucleic acid-ribonucleic acid hybridization has been detected in the induced wild-type (ara(+)) strain of Escherichia coli B/r as compared with the uninduced control, thus providing evidence that regulation of the positively controlled l-arabinose operon is at the level of transcription.

The ribosome-polyuridylic acid-phenylalanyl-soluble ribonucleic acid complex has been shown to be an intermediate in the synthesis of polyphenylalanine. About half of the phenylalanine incorporated into polypeptide from the complex was located in the N-terminus. The formation of this ribosomal complex with phenylalanyl-soluble ribonucleic acid is rate-limiting in the synthesis of polyphenylalan...