Nucleoside monophosphate pools in BU-induced filaments of Escherichia coli K-12

5-Broznouracil (BU) caused qualitative and quantitative changes in the nucleoside monophosphate pools in Escherichia coli Thy - His - which had been previously starved for histidine. The changes in the nucleoside monophosphate pools were apparent as early as 120 minutes during BU-incubation. When cells were grown in the presence of 32Pi, NAD, AMP, CMP, dADP, were not detected. There was a significant increase in GMP, UMP CDP, dCDP, and TMP. The "weakly-binding" BU-compound, was found to be a dinucleoside monophosphate and when subjected to phosphodiesterase yielded 5-BUR and '5-AMP. The dinucleoside monophosphate is probably a catabolic product or RNA. 2-14C-5-BU was incorporated into RNA.