Rv1773 is a transcriptional repressor deleted from BCG-Pasteur

SummaryMycobacterium bovis Bacille Calmette-Guérin (BCG) is a live attenuated vaccine for the prevention of tuberculosis. Transcriptome comparison reveals dysegulated expression of two genes, Rv1774 and Rv1775, exclusively in the Pasteur strain of BCG. We show that these genes form a bicistronic operon regulated by Rv1773, a transcriptional repressor deleted during the in vitro evolution of BCG.