THE ROLE OF DEOXYRIBONUCLEIC ACID AND OTHER POLYNUCLEOTIDES IN ATP SYNTHESIS BY ISOLATED CELL NUCLEI

Abstract

Isolated cell nuclei deprived of their DNA lose their capacity to synthesize adenosine triphosphate. This capacity can be restored to them by the addition of a polynucleotide supplement, provided that oxygen is present. Both DNA and RNA can function in this way. The role of polynucleotides as "cofactors" for ATP synthesis is discussed in connection with their role in the formation of cell proteins. One function of polynucleotides, including both ribo- and deoxyrlbonuclelc acids, is to mediate the synthesis of adenosine triphosphate. Their role in this process would localize the ATP at the site of protein synthesis, where it is needed for amino acid activation. It is now widely accepted that the nucleic acids also determine the specificity of protein synthetic reactions. Their role in ATP synthesis thus offers another example, now on the molecular level, of the highly integrated functional organization so characteristic of biological systems. The fact that small, relatively simple polynucleotides can function in ATP synthesis is also of interest from the evolutionary point of view. It may be that this was the original role of the polynucleotide structure and that the evolution of the cell brought with it a parallel molecular evolution in which these nonspecific polysaccharide molecules were gradually branched and modified to take on a new complexity and assume a new function: a role in the transmission of hereditary specificity.