Expression, Purification and Crystallization of the Mycobacterium Tuberculosis HsP16.3 Molecular Chaperone Background of Mycobacterium Tuberculosis HSP16.3 HSP16.3, a 16.3 kDa protein from Mycobacterium Tuberculosis, was originally identified as a prominent antigen( Kingston et al., 1987). During the stationary phase HSP16.3 is maximally expressed and becomes a main protein of the latent phase (Yuan et al., 1996). Previous studies showed that HSP16.3 can make the cell structure stable and prevent stationary Mycobacterium Tuberculosis from autoly sing ( Cunningham et al., 1998). In previous studies, HSP16.3 was found as one of thea -crystall in-related small heat shock proteins(sHSP) with molecular chaperone activ ity Experiments in vitro revealed that HSP16. 3 can suppress the thermal aggregation of citrate synthase at 395C, without consumption of ATP( Chang et al., 1996) Now the Mycobacterium Tuberculosis HSP16.3 gene was cloned to the plasmid PSTE-HSP16.3, and transformed to E Coli. BL21(DE3)strain Material and method Expression Things to have ready before Starting -Plate or glycerol culture Sterile LB 25ml in a 50mL shaker flasker. 250ml in a 500mL shaker lasker. all together autoclaved, antibiotic added afterword antibiotic and sterile waterExpression, Purification and Crystallization of the Mycobacterium Tuberculosis HSP16.3 Molecular Chaperone Background of Mycobacterium Tuberculosis HSP16.3 HSP16.3, a 16.3 kDa protein from Mycobacterium Tuberculosis, was originally identified as a prominent antigen (Kingston et al., 1987). During the stationary phase, HSP16.3 is maximally expressed and becomes a main protein of the latent phase (Yuan et al., 1996). Previous studies showed that HSP16.3 can make the cell structure stable and prevent stationary Mycobacterium Tuberculosis from autolysing (Cunningham et al., 1998). In previous studies, HSP16.3 was found as one of theα -crystallin-related small heat shock proteins (sHSP) with molecular chaperone activity. Experiments in vitro revealed that HSP16.3 can suppress the thermal aggregation of citrate synthase at 39.5˚C, without consumption of ATP (Chang et al., 1996). Now the Mycobacterium Tuberculosis HSP16.3 gene was cloned to the plasmid pSTE-HSP16.3, and transformed to E.Coli. BL21(DE3) strain. Material and Method Expression Things to have ready before Starting. -Plate or glycerol culture -Sterile LB 25ml in a 50mL shaker flasker, 250ml in a 500mL shaker flasker, all together autoclaved, antibiotic added afterword. - antibiotic and sterile water - Tips