5-Bromouracil-Induced Filaments of Escherichia coli

A dinucleoside monophosphate was isolated from 5-bromouracil-induced filaments of a thymine auxotroph of Escherichia coli K-12. The dinucleoside monophosphate was fractioned from a ["C]5-bromouracil-labeled perchloric acid extract using Dowex-1-formate ion-exchange chromatography. Sephadex chromatography revealed its molecular weight to be 710. Snake venom phosphodiesterase digest of the dinucleoside monophosphate yielded [4C ]5-bromouridine and adenosine 5'-monophosphate. The presence of [4C ]5-bromouracil in bacterial ribonucleic acid indicates that ribonucleic acid, which had incorporated 5-bromouracil, was the probable source of this dinucleoside monophosphate, 5-bromouridylyl-(3' -5')-adenosine.