PRESENCE OF PROTEIN CONSTITUENTS OF THE GRAM-POSITIVE BACTERIAL PHOSPHOTRANSFERASE REGULATORY SYSTEM IN ACHOLEPLASMA-LAIDLAWII

Acholeplasma species have been reported to lack a functional phosphoen olpyruvate:sugar phosphotransferase system (PTS). We show here that Ac holeplasma laidlawii possesses activities of enzyme I, HPr, HPr(ser) k inase, and HPr(ser-P) phosphatase but lacks detectable activities of e nzymes II of the PTS. HPr from this organism was purified, and the reg ulatory properties of the kinase and phosphatase were characterized an d shown to differ from those of previously studied bacteria. The resul ts suggest the presence of an incomplete PTS in A. laidlawii which has the potential to function in a unique regulatory capacity.