Mutations in deoB and deoC alter an extracellular signaling pathway required for activation of the gab operon in Escherichia coli.

In Escherichia coli, a lacZ fusion to the gabT gene is activated by the accumulation of two self-produced extracellular signals, indole and a second unidentified signal (signal-2). Extracellular indole contributes approximately 25% of this activation and signal-2 is responsible for the majority of activation. Using an E.

Escherichia coli genes regulated by cell-to-cell signaling.

Utilizing the bicistronic reporter transposon mini-Tn5 lacZ-tet/1, we have identified lacZ fusions to four Escherichia coli genes/operons that are strongly activated by the accumulation of self-produced extracellular signals. These fusions were designated cma9, cma48, cma113, and cma114 for conditioned medium activated. Each of the cma fusions was expressed in a growth phase-dependent manner, and the presence of conditioned medium from a stationary phase E.