The carboxyl terminal domain of Escherichia coli DNA topoisomerase I confers higher affinity to DNA.

@article{BeranSteed1989TheCT,
  title={The carboxyl terminal domain of Escherichia coli DNA topoisomerase I confers higher affinity to DNA.},
  author={R K Beran-Steed and Y. C. Tse-Dinh},
  journal={Proteins},
  year={1989},
  volume={6 3},
  pages={249-58}
}
Limited digestion of E. coli DNA topoisomerase I with trypsin or papain generated a DNA-binding domain of MW 14,000 corresponding to the carboxyl terminal of the enzyme. This fragment binds to single-stranded DNA agarose as tightly as the intact enzyme. It required around 400 mM NaCl for elution. A truncated topoisomerase that lacks this C-terminal domain… CONTINUE READING