Studies on protein and nucleic acid metabolism in virus-infected mammalian cells. 1. Encephalomyocarditis virus in Krebs II mouse-ascites-tumour cells

Abstract

Many attempts have been made during recent years to define the relationship between protein and nucleic acid biosynthesis. There is now ade- quate evidence that soluble proteins such as ribonuclease, insulin or haemoglobin have fully- defined chemical structures, each with a defined amino acid sequence. These sequences appear to be under genetic control and numerous hypotheses have been advanced to explain the control mechanism. In essence, they are all variants of one proposition, that protein synthesis takes place upon a template. Only three types of molecule have been considered as serious candidates for this role, deoxyribonucleic acid, ribonucleic acid and protein. Although deoxyribonucleic acid is closely associated with the genetic apparatus, current evidence favours ribonucleic acid as the macro- molecule most closely associated with protein synthesis. There seems no doubt that ribonucleic acid can carry the necessary information for control of protein synthesis; thus, for example, ribonucleic acid from tobacco mosaic virus can induce the synthesis of strain-specific tobacco mosaic protein It seems quite likely therefore that ribonucleic acid could act as a template for protein synthesis, but no direct demonstration of this function has been achieved.