RESUMEN
In today’s era tuberculosis is a major threat to human population. The lethality of this disease is caused by very efficientlythrived bacteria Mycobacterium tuberculosis (M. tuberculosis). Ca2? plays crucial role in maintenance of cellular homeostasis. Bacilli survival in human alveolar macrophages majorly depends on disruption in Ca2? signaling. Bacilli sustainability in phagosome lies in the interruption of phagolysosomal fusion, which is possible because of low intracellularCa2? concentration. Bacilli contain various Ca2? binding proteins which help in regulation of Ca2? signaling for its ownbenefit. For the survival of pathogen, it requires alteration in normal Ca2? concentration in healthy cell. In this review weaim to find the various Ca2? binding domains which are present in several Ca2? binding proteins of M. tuberculosis andvariety of roles played by Ca2? to survive bacilli within host cell. This manuscript emphasizes the Ca2? binding domainspresent in PE_PGRS group of gene family and their functionality in M. tuberculosis survival and pathogenesis.