Lsr2 is a nucleoid-associated protein that exerts pleiotropic effects on mycobacterial cellular processes

Lsr2 is involved in maintaining chromosome structure in asymmetrically dividing mycobacteria and is essential in the tubercle bacillus (M. tuberculosis) during infection. Here, we report that a lack of Lsr2 profoundly impacts the mycobacterial cell morphology and the properties of the cell envelope resulting in the formation of smooth, short and antibiotics sensitive cells. Lsr2 forms large and dynamic nucleoprotein complexes in vivo and deletion of lsr2 gene exerts a profound effect on the replication time and replisome dynamics. We suggest that the Lsr2 nucleoprotein complexes may contribute to maintaining the proper organization of the newly synthesized DNA. Moreover, we demonstrate that the N-terminal oligomerization domain of Lsr2 is indispensable for the formation of nucleoprotein complexes in vivo. Collectively, our results indicate that Lsr2 exerts a pleiotropic effect on cellular processes and appears to be an attractive target for the development of a novel antitubercular drugs.