RNase G controls tpiA mRNA abundance in response to oxygen availability in Escherichia coli.

Studies have shown that many enzymes involved in glycolysis are upregulated in Escherichia coli endoribonuclease G (rng) null mutants. However, the molecular mechanisms underlying the RNase G-associated regulation of glycolysis have not been characterized. Here, we show that RNase G cleaves the 5' untranslated region of triosephosphate isomerase A (tpiA) mRNA, leading to destabilization of the mRNA in E. coli. Nucleotide substitutions within the RNase G cleavage site in the genome resulted in altered tpiA mRNA stability, indicating that RNase G activity influences tpiA mRNA abundance. In addition, we observed that tpiA expression was enhanced, whereas that of RNase G was decreased, in E. coli cells grown anaerobically. Our findings suggest that RNase G negatively regulates tpiA mRNA abundance in response to oxygen availability in E. coli.