FIG. 2.
Purification of X-PBP. (A) Scheme of X-PBP purification. AmSO4, ammonium sulfate. (B) Mobility shift assay of Poros HQ column fractions. FT, flowthrough. (C) Mobility shift assay of input and unbound fractions from the DNA affinity purification. The unbound fraction from the mutant DNA resin retained as high a level of X-PBP activity as the input. In contrast, the unbound fraction from the wild-type DNA resin was depleted of X-PBP activity. (D) Silver staining analysis of input, unbound, and eluted fractions of DNA affinity purification. A 68-kDa protein was specifically bound to the wild-type DNA resin and eluted specifically with the wild-type X minimal promoter DNA. M, mutant; W, wild type.