Positively regulates the expression of the NorB efflux pump and negatively regulates the expression of the AbcA efflux pump. Binds specifically to the promoters of norA, norB and norC and abcA genes. Could also have an aminotransferase activity (By similarity). In the C-terminal section; belongs to the class-I pyridoxal-phosphate-dependent aminotransferase family.