title: Overproduction and rapid purification of the phosphoenolpyruvate:sugar phosphotransferase system proteins enzyme I, HPr, and Protein IIIGlc of Escherichia coli.
abstract: We present methods for the rapid, simple purification of Enzyme I, HPr, and Protein IIIGlc of the Escherichia coli phosphoenolpyruvate:sugar phosphotransferase system (PTS) using plasmids overproducing gene products. The gene for HPr (ptsH) was cloned into the expression vector pKC30. A simple procedure was devised for the purification to homogeneity of this protein from extracts of heat-induced cells containing pKC30/ptsH recombinant clone. The genes for Enzyme I (ptsI) and Protein IIIGlc (crr) were cloned separately into the expression vector pRE1. Rapid purification procedures were developed for the isolation of homogeneous preparations of these two proteins from extracts of heat-induced cells containing pRE1/ptsI and pRE1/crr recombinants. From about 6 g of cells, these procedures yielded 100, 86, and 50 mg of Enzyme I, HPr, and Protein IIIGlc, respectively. The activity of the proteins purified by these methods was comparable to that of the proteins isolated by previously published less efficient procedures.
authors.affiliation: Center for Advanced Research in Biotechnology, National Institute of Standards and Technology, Rockville, Maryland 20850.
authors.forename: P
authors.initials: P
authors.lastname: Reddy
authors.forename: N
authors.initials: N
authors.lastname: Fredd-Kuldell
authors.forename: E
authors.initials: E
authors.lastname: Liberman
authors.forename: A
authors.initials: A
authors.lastname: Peterkofsky
mesh_terms: D001483:Base Sequence; D002850:Chromatography, Gel; D002852:Chromatography, Ion Exchange; D003001:Cloning, Molecular; D004269:DNA, Bacterial / Q000235:genetics; D004591:Electrophoresis, Polyacrylamide Gel; D004926:Escherichia coli / Q000201:enzymology* / Q000235:genetics; D008969:Molecular Sequence Data; D010731:Phosphoenolpyruvate Sugar Phosphotransferase System / Q000096:biosynthesis / Q000235:genetics / Q000302:isolation & purification*; D010957:Plasmids; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000235:genetics / Q000302:isolation & purification
chemical_list: D004269:DNA, Bacterial; D011994:Recombinant Proteins; D010731:Phosphoenolpyruvate Sugar Phosphotransferase System