Changes in the Concentrations of Guanosine 5′-Diphosphate 3′-Diphosphate and the Initiating Nucleoside Triphosphate Account for Inhibition of rRNA Transcription in Fructose-1,6-Diphosphate Aldolase ( fda ) Mutants

Abstract

ABSTRACT Early screens for conditional lethal mutations that affected rRNA expression in Escherichia coli identified temperature-sensitive fda mutants ( fda encodes the glycolytic enzyme fructose-1,6-diphosphate aldolase). It was shown that these fda (Ts) mutants were severely impaired in rRNA synthesis upon shift to the restrictive temperature, although the mechanism of inhibition was never determined. Here, we bring resolution to this long-standing question by showing that changes in the concentrations of guanosine 5′-diphosphate 3′-diphosphate and initiating nucleoside triphosphates can account for the previously observed effects of fda mutations on rRNA transcription.