Removal of impurities from transcription factor preparations that alter their DNA-binding properties

Academic Article
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publication date

  • August 2002

abstract

  • Biochemical studies of transcriptional activators are important for understanding their detailed mechanism of action. Such experiments generally employ chimeric constructs comprised of fused DNA- binding and activation domains that are expressed in, and purified from, Escherichia coli, since full-length activators are usually difficult to express. We report here that such preparations contain chaperone impurities that affect the DNA-binding properties of the activator, for example sharply reducing the half-life of the protein-DNA complex. A simple method to remove these troublesome contaminants is described.