Escherichia coli Phosphoenolpyruvate Dependent Phosphotransferase System. Copurification of HPr and C Y - 6 Glucant
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چکیده
A rapid, high-yield procedure has been developed for the purification of HPr from the Escherichia coli phosphoenolpyruvate dependent phosphotransferase system. During this procedure, the protein copurifies with a 2500dalton homopolysaccharide which we have identified as (Y 1-6 T h e phosphoenolpyruvate dependent hexose transport system is, relative to the number of macromolecules involved, a rather simple, energy-dependent, transport system. As characterized by Roseman and co-workers (Roseman, 1969) the system is composed of one soluble carrier protein, HPr, one soluble enzyme, El, and a membrane-bound complex, Ell. It catalyzes the following reactions. PEP’ + HPr c-* P-HPr + pyruvate P-HPr + hexose (out) +-+ hexose-P (in) + HPr
منابع مشابه
Escherichia coli phosphoenolpyruvate-dependent phosphotransferase system: mechanism of phosphoryl-group transfer from phosphoenolpyruvate to HPr.
The mechanism of phosphoryl-group transfer from phosphoenolpyruvate (PEP) to HPr, catalyzed by enzyme I of the Escherichia coli PEP-dependent phosphotransferase system, has been studied in vitro. Steady-state kinetics and isotope exchange measurements revealed that this reaction cannot be described by a classical ping-pong mechanism although phosphoenzyme I acts as an intermediate. The kinetic ...
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تاریخ انتشار 2017