Mutational analysis of 39 residues of vaccinia DNA topoisomerase identifies Lys-220, Arg-223, and Asn-228 as important for covalent catalysis.

@article{Cheng1997MutationalAO,
  title={Mutational analysis of 39 residues of vaccinia DNA topoisomerase identifies Lys-220, Arg-223, and Asn-228 as important for covalent catalysis.},
  author={Clement J Cheng and Li Kai Wang and Junichi Sekiguchi and Stewart Shuman},
  journal={The Journal of biological chemistry},
  year={1997},
  volume={272 13},
  pages={8263-9}
}
Vaccinia DNA topoisomerase, a 314-amino acid type I enzyme, catalyzes the cleavage and rejoining of DNA strands through a DNA-(3'-phosphotyrosyl)-enzyme intermediate. To identify amino acids that participate in the transesterification reaction, we introduced alanine substitutions at 39 positions within a conserved 57amino acid segment upstream of the active-site tyrosine. Purified wild type and mutant proteins were compared with respect to their activities in relaxing supercoiled DNA. The… CONTINUE READING

Similar Papers

Loading similar papers…