title: Purification of Thermus aquaticus DNA polymerase expressed in Escherichia coli.
abstract: DNA polymerase from Thermus aquaticus has become a common reagent in molecular biology because of its utility in DNA amplification and DNA sequencing protocols. A simplified method is described here for isolating the recombinant Taq enzyme after overproduction in Escherichia coli. Purification requires 8 to 10 h and entails heat treating and clearing the E. coli lysate, followed by precipitation of the enzyme with polyethyleneimine and elution from Bio Rex 70 ion exchange resin in a single salt step. The resulting enzyme preparation contains a single, nearly homogeneous protein consistent with the previously established size of the Taq DNA polymerase in a yield of 40-50 mg of protein per liter of cell culture.
authors.affiliation: Department of Biological Chemistry, University of Michigan, Ann Arbor 48109.
authors.forename: D R
authors.initials: DR
authors.lastname: Engelke
authors.forename: A
authors.initials: A
authors.lastname: Krikos
authors.forename: M E
authors.initials: ME
authors.lastname: Bruck
authors.forename: D
authors.initials: D
authors.lastname: Ginsburg
mesh_terms: D001483:Base Sequence; D011232:Chemical Precipitation; D002852:Chromatography, Ion Exchange; D004259:DNA-Directed DNA Polymerase / Q000096:biosynthesis / Q000235:genetics / Q000302:isolation & purification*; D004926:Escherichia coli / Q000201:enzymology / Q000235:genetics*; D008969:Molecular Sequence Data; D010957:Plasmids; D011094:Polyethyleneimine; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000302:isolation & purification; D019914:Taq Polymerase; D013824:Thermus / Q000201:enzymology* / Q000235:genetics
chemical_list: D011994:Recombinant Proteins; D011094:Polyethyleneimine; D019914:Taq Polymerase; D004259:DNA-Directed DNA Polymerase