CONSTRUCTION OF HIS(6)-TAGGING VECTORS ALLOWING SINGLE-STEP PURIFICATION OF GROES AND OTHER POLYPEPTIDES PRODUCED IN BACILLUS-SUBTILIS

Two plasmid expression vectors for Bacillus subtilis have been constru cted that direct the synthesis of fusion proteins containing a stretch of six histidine residues (His(6)) at either the N or C terminus. The His(6) tag allows the rapid enrichment of proteins by metal chelate a ffinity chromatography in a denatured or native state. As an example o f the general utility of one of these expression vectors, we produced the GroES protein encoded by the groESL operon of B. stearothermophilu s.