IDENTIFICATION OF THE N-TERMINAL DOMAIN OF ENZYME-I OF THE ESCHERICHIA-COLI PHOSPHOENOLPYRUVATE-SUGAR PHOSPHOTRANSFERASE SYSTEM PRODUCED BYPROTEOLYTIC DIGESTION

The phosphoenolpyruvate:sugar phosphotransferase system of bacteria pl ays an important role in the concomitant uptake and phosphorylation of numerous sugars. The first protein in the pathway of phosphotransfer of the phosphoenolpyruvate:sugar phosphotransferase system is Enzyme I . It has been shown that a stable N-terminal domain can be produced by treatment of the purified protein with various proteolytic enzymes. W e show here that the region from glutamate-252 to leucine-264 is acces sible to proteolysis resulting in N-terminal cores ranging from M(r) 2 7521 to 28799. (C) 1994 Academic Press, Inc.