Effect of Energy Supply on Enzyme Induction by Pyrimidine Requiring Mutants of Escherichia Coli

A study of the formation of induced (adaptive) enzymes in purine or pyrimidine requiring mutants of Escherichia coli was reported in a previous publication (Pardee, 1954). The idea that synthesis of ribonucleic acid (RNA) is essential for protein synthesis is supported by the inability of the bacterial mutants to form protein and several enzymes, including f3-galactosidase, in the absence of purines or pyrimidines. All of these experiments were performed in a medium which contained an energy supply other than the inducer. Early in the work, it was noted, however, that in a medium which lacked both an energy supply and the nucleic acid component, formation of the induced enzyme did proceed to a considerable extent. The explanation of this phenomenon seems to lie in certain complications not pertinent to the relation of nucleic acid and protein syn-thesis and is the subject of this communication.