EcoRI variant N199H has enhanced specific activity.

@article{Kim1996EcoRIVN,
  title={EcoRI variant N199H has enhanced specific activity.},
  author={J J Kim and Kyeong Tae Min and Myeong Ho Kim and Sirk June Augh and By Do-Hyun Kim and Dr. Sor-Cheng Lee},
  journal={Gene},
  year={1996},
  volume={171 1},
  pages={129-30}
}
The Asn199 residue of the EcoRI restriction endonuclease has been replaced with other amino acids to investigate whether it mediates nucleotide recognition or catalytic activity. Cassette mutagenesis gave variants of EcoRI: N199D, N199H, N199L, N199R, N199S and N199V. Their relative cleavage rates were found to be in the following order: N199H > EcoRI (wild… CONTINUE READING