Deletions at the carboxyl terminus of vaccinia DNA topoisomerase affect DNA binding and enhance distributivity in DNA relaxation.

@article{Wang1997DeletionsAT,
  title={Deletions at the carboxyl terminus of vaccinia DNA topoisomerase affect DNA binding and enhance distributivity in DNA relaxation.},
  author={Li Kai Wang and Stewart Shuman},
  journal={Biochemistry},
  year={1997},
  volume={36 13},
  pages={3909-16}
}
Vaccinia topoisomerase relaxes DNA through the formation of a covalent DNA-(3'-phosphotyrosyl)protein intermediate at sites containing the sequence 5'-(T/C)CCTT/. The active site, Tyr-274, is situated near the carboxyl terminus of the 314 amino acid enzyme. Here, we report the effects of serial C-terminal deletions. Removal of five amino acids had no effect on topoisomerase activity. However, deletion of 10, 15, or 20 amino acids rendered the enzyme distributive in DNA relaxation, incrementally… CONTINUE READING