Mce3R, a TetR-type transcriptional repressor, controls the expression of a regulon involved in lipid metabolism in Mycobacterium tuberculosis.

The mce operons constitute four homologous regions in the Mycobacterium tuberculosis genome, each of which has 8-13 ORFs. Although the function of the Mce protein family has not been clearly established, its members are believed to be membrane lipid transporters. Based on functional experiments, we found that the regulator of the mce3 locus, Mce3R, negatively regulates the expression of the Rv1933c-Rv1935c and Rv1936-Rv1941 transcriptional units.