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R B ROBERTS

Publications and source records attributed to R B ROBERTS.

16 recordsLinked to original sources

The synthesis of ribosomes in E. coli. IV. The synthesis of ribosomal protein and the assembly of ribosomes.

The incorporation of C(14) leucine into the protein moiety of ribosomes has been studied as a sequel to the studies of ribosomal RNA synthesis. In contrast to the latter studies, labeled leucine is incorporated directly into 50S and 30S ribosomes without measurable delay by precursor stages. There is, however, evidence of some transfer of radioactivity from the 43S group of particles to the 50S. The inhibition of protein synthesis by chloramphenicol results in the accumulation of material similar to the eosome-the primary precursor in ribosome synthesis. There is also evidence for the synthesis of some neosome. The results of the studies of ribosomal RNA and protein synthesis are combined into a model of ribosome synthesis. Finally, consideration is made of the significance of these studies of ribosome synthesis for general problems of protein synthesis and information transfer.

Escherichia coli↗

A model for the mechanism of enzyme induction.

A sequence of reactions is postulated from which are derived equations describing the time course of enzyme induction. The model also yields the observed effect of the inducer concentration on the time constant and final rate of enzyme synthesis. Features of the model are: (a) The inducer acts first to release the protein forming template from its site of synthesis on the gene. (b) The inducer is involved again in the equilibrium dissociation of the free template-inducer complex which is utilized in the synthesis of the enzyme-forming unit. (c) The final enzyme-forming unit is unstable and must be synthesized continuously to maintain enzyme synthesis.

Enzyme Induction↗