Deletion of SenX3-RegX3, a key two-component regulatory system of Mycobacterium smegmatis, results in growth defects under phosphate-limiting conditions.

Two component regulatory systems are key elements in the control of bacterial gene expression in response to environmental perturbations. The SenX3-RegX3 system is implicated in the control of phosphate uptake in Mycobacterium smegmatis and Mycobacterium tuberculosis. regX3 is reported to be essential in M.