A Suggested Role of Amino-acids in Deoxyribonucleic Acid

Abstract

SEVERAL investigators have found amino-acids among the hydrolysis products of DNA's from many sources and some have suggested that small peptides may play a part in DNA structure and/or function. These have been reviewed by Bendich and Rosenkranz¹. We have considered the possibility that such small peptides are concerned with the regulation of enzyme synthesis. For this reason we have examined the amino-acid residues found in samples of DNA from Escherichia coli grown in ‘minimal’ and in ‘complete’ media. Bacteria grown in minimal media must synthesize large numbers of compounds not made by those grown in complete media. Therefore, more enzymes should be formed and more DNA should be functional in bacteria grown in minimal media. If control of DNA function is exerted through firmly bound amino-acids and peptides, then DNA from bacteria grown under these two sets of conditions should contain different amounts of amino-acids.