FIG. 3.

Addition of dnaY enhances the expression of the fusion protein. The expression of proteins in E. coli strains carrying pMAL or pDR4 was analyzed in the presence (+) and absence (−) of pUBS520 (dnaY). The cells were harvested 2 h after the addition of IPTG, and equivalent amounts of sample were analyzed by SDS-PAGE. Lanes: 1 and 2, E. coli cells; 3 and 4, E. coli cells with pMAL; 5 and 6, E. coli cells with pDR4. The samples in lanes 2, 4, and 6 contained the dnaY gene, which encodes an arginyl tRNA. The positions of the 92-kDa malE-AF0394 fusion product and the malE product (MBP) are indicated.