An ArsR-like transcriptional factor recognizes a conserved sequence motif and positively regulates the expression of phoP in mycobacteria

► In this study, we characterize an ArsR transcriptional factor as the first regulator of phoP in both mycobacterial species. ► An inverted repeat sequence motif is successfully mapped out for the recognition of ArsR. ► The ArsR regulator is shown to positively regulate the expression of phoP in Mycobacterium smegmatis.