OVERPRODUCTION AND PURIFICATION OF THE MYCOPLASMA CAPRICOLUM PHOSPHOCARRIER PROTEIN, HPR, OF THE PHOSPHOENOLPYRUVATE - SUGAR PHOSPHOTRANSFERASE SYSTEM

The gene (ptsH) for the phosphocarrier protein, HPr, of the phosphoeno lpyruvate:sugar phosphotransferase system from Mycoplasma capricolum w as previously cloned and sequenced. We present here the results of exp eriments in which the ptsH gene was cloned into a vector for high leve l expression in Escherichia coli of the phosphocarrier protein, Condit ions were developed for overproduction and purification of HPr by a tw o-column procedure. The purified protein, analyzed by Edman degradatio n and mass spectrometry, was found to have been processed by removal o f the N-terminal methionine residue. Examination of the purified prote in by gel electrophoresis under isoelectric focusing conditions reveal ed that it has an unusually high isoelectric point. (C) Academic Press , Inc.