Fig. 1.

Construction of MuSI expression vector and expression in E. coli B21 cells. a Schematic diagram of the MuSI expression vector. MuSI gene with BamHI and EcoRI restriction enzyme sites was subcloned downstream to the T7 promoter (T7 _P), generating the recombinant MuSI::pET28a(+) expression vector; 6xH six histidine-tagged resides; Amp ^R ampicillin resistance gene. b To examine whether MuSI gene was expressed in E. coli, western blotting with anti-His tag antibody was performed. Anti-DnaJ antibody was used as a control. V Cells with the empty vector, M cells with the MuSI::pET28a(+) expression vector. c MuSI protein expression in crude protein extract and purified protein extract from E. coli cell expressing MuSI. M Protein marker, V crude protein extract from cells with the empty vector, CM crude protein extract from cells with the MuSI expression vector; PM purified MuSI protein form cells with the MuSI expression vector. d Stress tolerance of E. coli expressing MuSI in the presence of 1.0 mM (upper) or 1.5 mM (lower) CdCl₂. Vector Cells with the empty vector, MuSI cells with the MuSI::pET28a(+) expression vector