Materials and methods
Cloning and expression of recombinantSK
ORF of the gene (Rv2539; MSMEG 3031) was PCR amplified using genomic DNA of H37Rv and M.smegmatis and then ligated into TA vector. Further, the gene was sub-cloned in pET28a (In vitrogen) expression vector and introduced intoE.coli BL21 (DE3).For expression of Rv2539 (MTSK) and MSMEG 3031 (MSSK), cultures were induced with 1.0 mM IPTG at 18°C, and 0.8mM IPTG at 22°C respectively. The expressed proteins were purified through Ni-NTA column (Qiagen).