1.3.7.4 | recombinant His-tagged enzyme from Escherichia coli strain BL21(DE3) by nickel affinity chromatography, anion exchange chromatography, and gel filtration. The PPhiB synthase monomer is contained in the major peak of anion-exchange chromatography, and the PPhiB synthase homodimer in the minor peak, for purification, the monomeric major peak fraction is used |