Iron is essential for the mycobacterium to survive and for its enzymatic action, according to Gokhale. It takes the iron from the host cell and to get it the mycobacterium develops siderophores, molecules synthesized by it for its own utility. The new anti-TB drugs being developed can use this pathway to attack the mycobacterium.
When the mycobacterium infects humans, it takes up residence in immune cells called macrophages. To survive in this harsh environment, the mycobacterium, like many other types of bacteria, need iron to carry out life-sustaining functions, such as creating proteins and synthesizing nucleotides to form DNA.
Gokhale's group identified the location of the genes that help the mycobacterium gather the iron more efficiently by observing that the expression of the genes, which increased significantly in response to low iron concentrations.