Important for survival of the bacterium in the host during infection. Promotes the survival of infected macrophages by activating multiple signaling responses and suppressing apoptosis of macrophages during nitrate stress. May contribute to the adaptation of M.tuberculosis during stress conditions by maintaining the cellular integrity. Can phosphorylate the FHA domain of Rv1747. ATP + L-seryl-[protein] = ADP + H(+) + O-phospho-L-seryl-[protein] ATP + L-threonyl-[protein] = ADP + H(+) + O-phospho-L-threonyl-[protein] Homodimer. Induced by nitric oxide stress. Repressed under oxidative stress. Autophosphorylated on serine and threonine residues. Dephosphorylated by PstP. Mutants show increased resistance to nitric oxide donors, increased sensitivity to reducing agents, and growth reduction at pH 7.0 and in the presence of lysozyme. They increase macrophage apoptosis, and exhibit lower rates of survival and multiplication in an in vitro macrophage model of infection. Belongs to the protein kinase superfamily. Ser/Thr protein kinase family.