Control of translation by the conformation of messenger RNA

This study concerns the question of whether protein biosynthesis is controlled by the conformation of messenger RNA. When R17 bacteriophage RNA was first incubated in the presence of Mg(++) before being used as messenger in a cell-free system from Escherichia coli, significant changes in the incorporation of phenylalanine and histidine into protein were seen. The amounts of proteins synthesized were also altered. The changes were not due to degradation of R17 RNA nor to denaturation of a contaminating repressor; they could be reversed by appropriate treatment of the RNA. There forms of R17 RNA are therefore postulated for the control mechanism and characterized by their translational behavior. The significance of these forms with respect to their conformation is discussed.